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7063fbf2 JB |
1 | /* -*- mode: c; c-basic-offset: 8; -*- |
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
3 | * | |
4 | * file.c - operations for regular (text) files. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public | |
8 | * License as published by the Free Software Foundation; either | |
9 | * version 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public | |
17 | * License along with this program; if not, write to the | |
18 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | * Boston, MA 021110-1307, USA. | |
20 | * | |
21 | * Based on sysfs: | |
22 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel | |
23 | * | |
24 | * configfs Copyright (C) 2005 Oracle. All rights reserved. | |
25 | */ | |
26 | ||
27 | #include <linux/fs.h> | |
28 | #include <linux/module.h> | |
7063fbf2 | 29 | #include <linux/slab.h> |
6d748924 | 30 | #include <linux/mutex.h> |
03607ace | 31 | #include <linux/vmalloc.h> |
7063fbf2 | 32 | #include <asm/uaccess.h> |
7063fbf2 JB |
33 | |
34 | #include <linux/configfs.h> | |
35 | #include "configfs_internal.h" | |
36 | ||
b23cdde4 JB |
37 | /* |
38 | * A simple attribute can only be 4096 characters. Why 4k? Because the | |
39 | * original code limited it to PAGE_SIZE. That's a bad idea, though, | |
40 | * because an attribute of 16k on ia64 won't work on x86. So we limit to | |
41 | * 4k, our minimum common page size. | |
42 | */ | |
43 | #define SIMPLE_ATTR_SIZE 4096 | |
7063fbf2 JB |
44 | |
45 | struct configfs_buffer { | |
46 | size_t count; | |
47 | loff_t pos; | |
48 | char * page; | |
49 | struct configfs_item_operations * ops; | |
6d748924 | 50 | struct mutex mutex; |
7063fbf2 | 51 | int needs_read_fill; |
03607ace PA |
52 | bool read_in_progress; |
53 | bool write_in_progress; | |
54 | char *bin_buffer; | |
55 | int bin_buffer_size; | |
7063fbf2 JB |
56 | }; |
57 | ||
58 | ||
59 | /** | |
60 | * fill_read_buffer - allocate and fill buffer from item. | |
61 | * @dentry: dentry pointer. | |
62 | * @buffer: data buffer for file. | |
63 | * | |
64 | * Allocate @buffer->page, if it hasn't been already, then call the | |
65 | * config_item's show() method to fill the buffer with this attribute's | |
66 | * data. | |
67 | * This is called only once, on the file's first read. | |
68 | */ | |
69 | static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buffer) | |
70 | { | |
71 | struct configfs_attribute * attr = to_attr(dentry); | |
72 | struct config_item * item = to_item(dentry->d_parent); | |
7063fbf2 JB |
73 | int ret = 0; |
74 | ssize_t count; | |
75 | ||
76 | if (!buffer->page) | |
77 | buffer->page = (char *) get_zeroed_page(GFP_KERNEL); | |
78 | if (!buffer->page) | |
79 | return -ENOMEM; | |
80 | ||
51798222 | 81 | count = attr->show(item, buffer->page); |
870823e6 | 82 | |
7063fbf2 | 83 | buffer->needs_read_fill = 0; |
b23cdde4 | 84 | BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE); |
7063fbf2 JB |
85 | if (count >= 0) |
86 | buffer->count = count; | |
87 | else | |
88 | ret = count; | |
89 | return ret; | |
90 | } | |
91 | ||
7063fbf2 JB |
92 | /** |
93 | * configfs_read_file - read an attribute. | |
94 | * @file: file pointer. | |
95 | * @buf: buffer to fill. | |
96 | * @count: number of bytes to read. | |
97 | * @ppos: starting offset in file. | |
98 | * | |
99 | * Userspace wants to read an attribute file. The attribute descriptor | |
100 | * is in the file's ->d_fsdata. The target item is in the directory's | |
101 | * ->d_fsdata. | |
102 | * | |
103 | * We call fill_read_buffer() to allocate and fill the buffer from the | |
104 | * item's show() method exactly once (if the read is happening from | |
105 | * the beginning of the file). That should fill the entire buffer with | |
106 | * all the data the item has to offer for that attribute. | |
107 | * We then call flush_read_buffer() to copy the buffer to userspace | |
108 | * in the increments specified. | |
109 | */ | |
110 | ||
111 | static ssize_t | |
112 | configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
113 | { | |
114 | struct configfs_buffer * buffer = file->private_data; | |
115 | ssize_t retval = 0; | |
116 | ||
6d748924 | 117 | mutex_lock(&buffer->mutex); |
7063fbf2 | 118 | if (buffer->needs_read_fill) { |
867fa491 | 119 | if ((retval = fill_read_buffer(file->f_path.dentry,buffer))) |
7063fbf2 JB |
120 | goto out; |
121 | } | |
4779efca | 122 | pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n", |
8e24eea7 | 123 | __func__, count, *ppos, buffer->page); |
92f4c701 AM |
124 | retval = simple_read_from_buffer(buf, count, ppos, buffer->page, |
125 | buffer->count); | |
7063fbf2 | 126 | out: |
6d748924 | 127 | mutex_unlock(&buffer->mutex); |
7063fbf2 JB |
128 | return retval; |
129 | } | |
130 | ||
03607ace PA |
131 | /** |
132 | * configfs_read_bin_file - read a binary attribute. | |
133 | * @file: file pointer. | |
134 | * @buf: buffer to fill. | |
135 | * @count: number of bytes to read. | |
136 | * @ppos: starting offset in file. | |
137 | * | |
138 | * Userspace wants to read a binary attribute file. The attribute | |
139 | * descriptor is in the file's ->d_fsdata. The target item is in the | |
140 | * directory's ->d_fsdata. | |
141 | * | |
142 | * We check whether we need to refill the buffer. If so we will | |
143 | * call the attributes' attr->read() twice. The first time we | |
144 | * will pass a NULL as a buffer pointer, which the attributes' method | |
145 | * will use to return the size of the buffer required. If no error | |
146 | * occurs we will allocate the buffer using vmalloc and call | |
147 | * attr->read() again passing that buffer as an argument. | |
148 | * Then we just copy to user-space using simple_read_from_buffer. | |
149 | */ | |
150 | ||
151 | static ssize_t | |
152 | configfs_read_bin_file(struct file *file, char __user *buf, | |
153 | size_t count, loff_t *ppos) | |
154 | { | |
155 | struct configfs_buffer *buffer = file->private_data; | |
156 | struct dentry *dentry = file->f_path.dentry; | |
157 | struct config_item *item = to_item(dentry->d_parent); | |
158 | struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry); | |
159 | ssize_t retval = 0; | |
160 | ssize_t len = min_t(size_t, count, PAGE_SIZE); | |
161 | ||
162 | mutex_lock(&buffer->mutex); | |
163 | ||
164 | /* we don't support switching read/write modes */ | |
165 | if (buffer->write_in_progress) { | |
166 | retval = -ETXTBSY; | |
167 | goto out; | |
168 | } | |
169 | buffer->read_in_progress = 1; | |
170 | ||
171 | if (buffer->needs_read_fill) { | |
172 | /* perform first read with buf == NULL to get extent */ | |
173 | len = bin_attr->read(item, NULL, 0); | |
174 | if (len <= 0) { | |
175 | retval = len; | |
176 | goto out; | |
177 | } | |
178 | ||
179 | /* do not exceed the maximum value */ | |
180 | if (bin_attr->cb_max_size && len > bin_attr->cb_max_size) { | |
181 | retval = -EFBIG; | |
182 | goto out; | |
183 | } | |
184 | ||
185 | buffer->bin_buffer = vmalloc(len); | |
186 | if (buffer->bin_buffer == NULL) { | |
187 | retval = -ENOMEM; | |
188 | goto out; | |
189 | } | |
190 | buffer->bin_buffer_size = len; | |
191 | ||
192 | /* perform second read to fill buffer */ | |
193 | len = bin_attr->read(item, buffer->bin_buffer, len); | |
194 | if (len < 0) { | |
195 | retval = len; | |
196 | vfree(buffer->bin_buffer); | |
197 | buffer->bin_buffer_size = 0; | |
198 | buffer->bin_buffer = NULL; | |
199 | goto out; | |
200 | } | |
201 | ||
202 | buffer->needs_read_fill = 0; | |
203 | } | |
204 | ||
205 | retval = simple_read_from_buffer(buf, count, ppos, buffer->bin_buffer, | |
206 | buffer->bin_buffer_size); | |
207 | out: | |
208 | mutex_unlock(&buffer->mutex); | |
209 | return retval; | |
210 | } | |
211 | ||
7063fbf2 JB |
212 | |
213 | /** | |
214 | * fill_write_buffer - copy buffer from userspace. | |
215 | * @buffer: data buffer for file. | |
3d0f89bb | 216 | * @buf: data from user. |
7063fbf2 JB |
217 | * @count: number of bytes in @userbuf. |
218 | * | |
219 | * Allocate @buffer->page if it hasn't been already, then | |
220 | * copy the user-supplied buffer into it. | |
221 | */ | |
222 | ||
223 | static int | |
224 | fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size_t count) | |
225 | { | |
226 | int error; | |
227 | ||
228 | if (!buffer->page) | |
ff05d1c4 | 229 | buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0); |
7063fbf2 JB |
230 | if (!buffer->page) |
231 | return -ENOMEM; | |
232 | ||
b23cdde4 JB |
233 | if (count >= SIMPLE_ATTR_SIZE) |
234 | count = SIMPLE_ATTR_SIZE - 1; | |
7063fbf2 JB |
235 | error = copy_from_user(buffer->page,buf,count); |
236 | buffer->needs_read_fill = 1; | |
ff05d1c4 JB |
237 | /* if buf is assumed to contain a string, terminate it by \0, |
238 | * so e.g. sscanf() can scan the string easily */ | |
239 | buffer->page[count] = 0; | |
7063fbf2 JB |
240 | return error ? -EFAULT : count; |
241 | } | |
242 | ||
243 | ||
244 | /** | |
245 | * flush_write_buffer - push buffer to config_item. | |
3d0f89bb | 246 | * @dentry: dentry to the attribute |
7063fbf2 | 247 | * @buffer: data buffer for file. |
3d0f89bb | 248 | * @count: number of bytes |
7063fbf2 JB |
249 | * |
250 | * Get the correct pointers for the config_item and the attribute we're | |
251 | * dealing with, then call the store() method for the attribute, | |
252 | * passing the buffer that we acquired in fill_write_buffer(). | |
253 | */ | |
254 | ||
255 | static int | |
256 | flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size_t count) | |
257 | { | |
258 | struct configfs_attribute * attr = to_attr(dentry); | |
259 | struct config_item * item = to_item(dentry->d_parent); | |
7063fbf2 | 260 | |
870823e6 | 261 | return attr->store(item, buffer->page, count); |
7063fbf2 JB |
262 | } |
263 | ||
264 | ||
265 | /** | |
266 | * configfs_write_file - write an attribute. | |
267 | * @file: file pointer | |
268 | * @buf: data to write | |
269 | * @count: number of bytes | |
270 | * @ppos: starting offset | |
271 | * | |
272 | * Similar to configfs_read_file(), though working in the opposite direction. | |
273 | * We allocate and fill the data from the user in fill_write_buffer(), | |
274 | * then push it to the config_item in flush_write_buffer(). | |
275 | * There is no easy way for us to know if userspace is only doing a partial | |
276 | * write, so we don't support them. We expect the entire buffer to come | |
277 | * on the first write. | |
278 | * Hint: if you're writing a value, first read the file, modify only the | |
279 | * the value you're changing, then write entire buffer back. | |
280 | */ | |
281 | ||
282 | static ssize_t | |
283 | configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
284 | { | |
285 | struct configfs_buffer * buffer = file->private_data; | |
3d0f89bb | 286 | ssize_t len; |
7063fbf2 | 287 | |
6d748924 | 288 | mutex_lock(&buffer->mutex); |
3d0f89bb JB |
289 | len = fill_write_buffer(buffer, buf, count); |
290 | if (len > 0) | |
7121064b | 291 | len = flush_write_buffer(file->f_path.dentry, buffer, len); |
3d0f89bb JB |
292 | if (len > 0) |
293 | *ppos += len; | |
6d748924 | 294 | mutex_unlock(&buffer->mutex); |
3d0f89bb | 295 | return len; |
7063fbf2 JB |
296 | } |
297 | ||
03607ace PA |
298 | /** |
299 | * configfs_write_bin_file - write a binary attribute. | |
300 | * @file: file pointer | |
301 | * @buf: data to write | |
302 | * @count: number of bytes | |
303 | * @ppos: starting offset | |
304 | * | |
305 | * Writing to a binary attribute file is similar to a normal read. | |
306 | * We buffer the consecutive writes (binary attribute files do not | |
307 | * support lseek) in a continuously growing buffer, but we don't | |
308 | * commit until the close of the file. | |
309 | */ | |
310 | ||
311 | static ssize_t | |
312 | configfs_write_bin_file(struct file *file, const char __user *buf, | |
313 | size_t count, loff_t *ppos) | |
314 | { | |
315 | struct configfs_buffer *buffer = file->private_data; | |
316 | struct dentry *dentry = file->f_path.dentry; | |
317 | struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry); | |
318 | void *tbuf = NULL; | |
319 | ssize_t len; | |
320 | ||
321 | mutex_lock(&buffer->mutex); | |
322 | ||
323 | /* we don't support switching read/write modes */ | |
324 | if (buffer->read_in_progress) { | |
325 | len = -ETXTBSY; | |
326 | goto out; | |
327 | } | |
328 | buffer->write_in_progress = 1; | |
329 | ||
330 | /* buffer grows? */ | |
331 | if (*ppos + count > buffer->bin_buffer_size) { | |
332 | ||
333 | if (bin_attr->cb_max_size && | |
334 | *ppos + count > bin_attr->cb_max_size) { | |
335 | len = -EFBIG; | |
336 | } | |
337 | ||
338 | tbuf = vmalloc(*ppos + count); | |
339 | if (tbuf == NULL) { | |
340 | len = -ENOMEM; | |
341 | goto out; | |
342 | } | |
343 | ||
344 | /* copy old contents */ | |
345 | if (buffer->bin_buffer) { | |
346 | memcpy(tbuf, buffer->bin_buffer, | |
347 | buffer->bin_buffer_size); | |
348 | vfree(buffer->bin_buffer); | |
349 | } | |
350 | ||
351 | /* clear the new area */ | |
352 | memset(tbuf + buffer->bin_buffer_size, 0, | |
353 | *ppos + count - buffer->bin_buffer_size); | |
354 | buffer->bin_buffer = tbuf; | |
355 | buffer->bin_buffer_size = *ppos + count; | |
356 | } | |
357 | ||
358 | len = simple_write_to_buffer(buffer->bin_buffer, | |
359 | buffer->bin_buffer_size, ppos, buf, count); | |
360 | if (len > 0) | |
361 | *ppos += len; | |
362 | out: | |
363 | mutex_unlock(&buffer->mutex); | |
364 | return len; | |
365 | } | |
366 | ||
367 | static int check_perm(struct inode * inode, struct file * file, int type) | |
7063fbf2 | 368 | { |
867fa491 JJS |
369 | struct config_item *item = configfs_get_config_item(file->f_path.dentry->d_parent); |
370 | struct configfs_attribute * attr = to_attr(file->f_path.dentry); | |
03607ace | 371 | struct configfs_bin_attribute *bin_attr = NULL; |
7063fbf2 JB |
372 | struct configfs_buffer * buffer; |
373 | struct configfs_item_operations * ops = NULL; | |
374 | int error = 0; | |
375 | ||
376 | if (!item || !attr) | |
377 | goto Einval; | |
378 | ||
03607ace PA |
379 | if (type & CONFIGFS_ITEM_BIN_ATTR) |
380 | bin_attr = to_bin_attr(file->f_path.dentry); | |
381 | ||
7063fbf2 JB |
382 | /* Grab the module reference for this attribute if we have one */ |
383 | if (!try_module_get(attr->ca_owner)) { | |
384 | error = -ENODEV; | |
385 | goto Done; | |
386 | } | |
387 | ||
388 | if (item->ci_type) | |
389 | ops = item->ci_type->ct_item_ops; | |
390 | else | |
391 | goto Eaccess; | |
392 | ||
393 | /* File needs write support. | |
394 | * The inode's perms must say it's ok, | |
395 | * and we must have a store method. | |
396 | */ | |
397 | if (file->f_mode & FMODE_WRITE) { | |
03607ace PA |
398 | if (!(inode->i_mode & S_IWUGO)) |
399 | goto Eaccess; | |
400 | ||
401 | if ((type & CONFIGFS_ITEM_ATTR) && !attr->store) | |
7063fbf2 JB |
402 | goto Eaccess; |
403 | ||
03607ace PA |
404 | if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->write) |
405 | goto Eaccess; | |
7063fbf2 JB |
406 | } |
407 | ||
408 | /* File needs read support. | |
409 | * The inode's perms must say it's ok, and we there | |
410 | * must be a show method for it. | |
411 | */ | |
412 | if (file->f_mode & FMODE_READ) { | |
03607ace PA |
413 | if (!(inode->i_mode & S_IRUGO)) |
414 | goto Eaccess; | |
415 | ||
416 | if ((type & CONFIGFS_ITEM_ATTR) && !attr->show) | |
417 | goto Eaccess; | |
418 | ||
419 | if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->read) | |
7063fbf2 JB |
420 | goto Eaccess; |
421 | } | |
422 | ||
423 | /* No error? Great, allocate a buffer for the file, and store it | |
424 | * it in file->private_data for easy access. | |
425 | */ | |
f8314dc6 | 426 | buffer = kzalloc(sizeof(struct configfs_buffer),GFP_KERNEL); |
559c9ac3 | 427 | if (!buffer) { |
7063fbf2 | 428 | error = -ENOMEM; |
559c9ac3 CS |
429 | goto Enomem; |
430 | } | |
6d748924 | 431 | mutex_init(&buffer->mutex); |
559c9ac3 | 432 | buffer->needs_read_fill = 1; |
03607ace PA |
433 | buffer->read_in_progress = 0; |
434 | buffer->write_in_progress = 0; | |
559c9ac3 CS |
435 | buffer->ops = ops; |
436 | file->private_data = buffer; | |
7063fbf2 JB |
437 | goto Done; |
438 | ||
439 | Einval: | |
440 | error = -EINVAL; | |
441 | goto Done; | |
442 | Eaccess: | |
443 | error = -EACCES; | |
559c9ac3 | 444 | Enomem: |
7063fbf2 JB |
445 | module_put(attr->ca_owner); |
446 | Done: | |
447 | if (error && item) | |
448 | config_item_put(item); | |
449 | return error; | |
450 | } | |
451 | ||
03607ace | 452 | static int configfs_release(struct inode *inode, struct file *filp) |
7063fbf2 | 453 | { |
867fa491 JJS |
454 | struct config_item * item = to_item(filp->f_path.dentry->d_parent); |
455 | struct configfs_attribute * attr = to_attr(filp->f_path.dentry); | |
7063fbf2 JB |
456 | struct module * owner = attr->ca_owner; |
457 | struct configfs_buffer * buffer = filp->private_data; | |
458 | ||
459 | if (item) | |
460 | config_item_put(item); | |
461 | /* After this point, attr should not be accessed. */ | |
462 | module_put(owner); | |
463 | ||
464 | if (buffer) { | |
465 | if (buffer->page) | |
466 | free_page((unsigned long)buffer->page); | |
6d748924 | 467 | mutex_destroy(&buffer->mutex); |
7063fbf2 JB |
468 | kfree(buffer); |
469 | } | |
470 | return 0; | |
471 | } | |
472 | ||
03607ace PA |
473 | static int configfs_open_file(struct inode *inode, struct file *filp) |
474 | { | |
475 | return check_perm(inode, filp, CONFIGFS_ITEM_ATTR); | |
476 | } | |
477 | ||
478 | static int configfs_open_bin_file(struct inode *inode, struct file *filp) | |
479 | { | |
480 | return check_perm(inode, filp, CONFIGFS_ITEM_BIN_ATTR); | |
481 | } | |
482 | ||
483 | static int configfs_release_bin_file(struct inode *inode, struct file *filp) | |
484 | { | |
485 | struct configfs_buffer *buffer = filp->private_data; | |
486 | struct dentry *dentry = filp->f_path.dentry; | |
487 | struct config_item *item = to_item(dentry->d_parent); | |
488 | struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry); | |
489 | ssize_t len = 0; | |
490 | int ret; | |
491 | ||
492 | buffer->read_in_progress = 0; | |
493 | ||
494 | if (buffer->write_in_progress) { | |
495 | buffer->write_in_progress = 0; | |
496 | ||
497 | len = bin_attr->write(item, buffer->bin_buffer, | |
498 | buffer->bin_buffer_size); | |
499 | ||
500 | /* vfree on NULL is safe */ | |
501 | vfree(buffer->bin_buffer); | |
502 | buffer->bin_buffer = NULL; | |
503 | buffer->bin_buffer_size = 0; | |
504 | buffer->needs_read_fill = 1; | |
505 | } | |
506 | ||
507 | ret = configfs_release(inode, filp); | |
508 | if (len < 0) | |
509 | return len; | |
510 | return ret; | |
511 | } | |
512 | ||
513 | ||
4b6f5d20 | 514 | const struct file_operations configfs_file_operations = { |
7063fbf2 JB |
515 | .read = configfs_read_file, |
516 | .write = configfs_write_file, | |
517 | .llseek = generic_file_llseek, | |
518 | .open = configfs_open_file, | |
519 | .release = configfs_release, | |
520 | }; | |
521 | ||
03607ace PA |
522 | const struct file_operations configfs_bin_file_operations = { |
523 | .read = configfs_read_bin_file, | |
524 | .write = configfs_write_bin_file, | |
525 | .llseek = NULL, /* bin file is not seekable */ | |
526 | .open = configfs_open_bin_file, | |
527 | .release = configfs_release_bin_file, | |
528 | }; | |
529 | ||
7063fbf2 JB |
530 | /** |
531 | * configfs_create_file - create an attribute file for an item. | |
532 | * @item: item we're creating for. | |
533 | * @attr: atrribute descriptor. | |
534 | */ | |
535 | ||
536 | int configfs_create_file(struct config_item * item, const struct configfs_attribute * attr) | |
537 | { | |
28444a2b AV |
538 | struct dentry *dir = item->ci_dentry; |
539 | struct configfs_dirent *parent_sd = dir->d_fsdata; | |
540 | umode_t mode = (attr->ca_mode & S_IALLUGO) | S_IFREG; | |
541 | int error = 0; | |
7063fbf2 | 542 | |
5955102c | 543 | inode_lock_nested(d_inode(dir), I_MUTEX_NORMAL); |
28444a2b AV |
544 | error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode, |
545 | CONFIGFS_ITEM_ATTR); | |
5955102c | 546 | inode_unlock(d_inode(dir)); |
28444a2b AV |
547 | |
548 | return error; | |
7063fbf2 JB |
549 | } |
550 | ||
03607ace PA |
551 | /** |
552 | * configfs_create_bin_file - create a binary attribute file for an item. | |
553 | * @item: item we're creating for. | |
554 | * @attr: atrribute descriptor. | |
555 | */ | |
556 | ||
557 | int configfs_create_bin_file(struct config_item *item, | |
558 | const struct configfs_bin_attribute *bin_attr) | |
559 | { | |
560 | struct dentry *dir = item->ci_dentry; | |
561 | struct configfs_dirent *parent_sd = dir->d_fsdata; | |
562 | umode_t mode = (bin_attr->cb_attr.ca_mode & S_IALLUGO) | S_IFREG; | |
563 | int error = 0; | |
564 | ||
5955102c | 565 | inode_lock_nested(dir->d_inode, I_MUTEX_NORMAL); |
03607ace PA |
566 | error = configfs_make_dirent(parent_sd, NULL, (void *) bin_attr, mode, |
567 | CONFIGFS_ITEM_BIN_ATTR); | |
5955102c | 568 | inode_unlock(dir->d_inode); |
03607ace PA |
569 | |
570 | return error; | |
571 | } |