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328970de | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
7063fbf2 JB |
2 | /* -*- mode: c; c-basic-offset: 8; -*- |
3 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
4 | * | |
5 | * file.c - operations for regular (text) files. | |
6 | * | |
7063fbf2 JB |
7 | * Based on sysfs: |
8 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel | |
9 | * | |
10 | * configfs Copyright (C) 2005 Oracle. All rights reserved. | |
11 | */ | |
12 | ||
13 | #include <linux/fs.h> | |
14 | #include <linux/module.h> | |
7063fbf2 | 15 | #include <linux/slab.h> |
6d748924 | 16 | #include <linux/mutex.h> |
03607ace | 17 | #include <linux/vmalloc.h> |
7c0f6ba6 | 18 | #include <linux/uaccess.h> |
7063fbf2 JB |
19 | |
20 | #include <linux/configfs.h> | |
21 | #include "configfs_internal.h" | |
22 | ||
b23cdde4 JB |
23 | /* |
24 | * A simple attribute can only be 4096 characters. Why 4k? Because the | |
25 | * original code limited it to PAGE_SIZE. That's a bad idea, though, | |
26 | * because an attribute of 16k on ia64 won't work on x86. So we limit to | |
27 | * 4k, our minimum common page size. | |
28 | */ | |
29 | #define SIMPLE_ATTR_SIZE 4096 | |
7063fbf2 JB |
30 | |
31 | struct configfs_buffer { | |
32 | size_t count; | |
33 | loff_t pos; | |
34 | char * page; | |
35 | struct configfs_item_operations * ops; | |
6d748924 | 36 | struct mutex mutex; |
7063fbf2 | 37 | int needs_read_fill; |
03607ace PA |
38 | bool read_in_progress; |
39 | bool write_in_progress; | |
40 | char *bin_buffer; | |
41 | int bin_buffer_size; | |
ff4dd081 AV |
42 | int cb_max_size; |
43 | struct config_item *item; | |
44 | struct module *owner; | |
45 | union { | |
46 | struct configfs_attribute *attr; | |
47 | struct configfs_bin_attribute *bin_attr; | |
48 | }; | |
7063fbf2 JB |
49 | }; |
50 | ||
b0841eef AV |
51 | static inline struct configfs_fragment *to_frag(struct file *file) |
52 | { | |
53 | struct configfs_dirent *sd = file->f_path.dentry->d_fsdata; | |
54 | ||
55 | return sd->s_frag; | |
56 | } | |
7063fbf2 | 57 | |
b0841eef | 58 | static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer) |
7063fbf2 | 59 | { |
b0841eef AV |
60 | struct configfs_fragment *frag = to_frag(file); |
61 | ssize_t count = -ENOENT; | |
7063fbf2 JB |
62 | |
63 | if (!buffer->page) | |
64 | buffer->page = (char *) get_zeroed_page(GFP_KERNEL); | |
65 | if (!buffer->page) | |
66 | return -ENOMEM; | |
67 | ||
b0841eef AV |
68 | down_read(&frag->frag_sem); |
69 | if (!frag->frag_dead) | |
70 | count = buffer->attr->show(buffer->item, buffer->page); | |
71 | up_read(&frag->frag_sem); | |
72 | ||
ff4dd081 AV |
73 | if (count < 0) |
74 | return count; | |
75 | if (WARN_ON_ONCE(count > (ssize_t)SIMPLE_ATTR_SIZE)) | |
76 | return -EIO; | |
ff4dd081 AV |
77 | buffer->needs_read_fill = 0; |
78 | buffer->count = count; | |
79 | return 0; | |
7063fbf2 JB |
80 | } |
81 | ||
7063fbf2 JB |
82 | /** |
83 | * configfs_read_file - read an attribute. | |
84 | * @file: file pointer. | |
85 | * @buf: buffer to fill. | |
86 | * @count: number of bytes to read. | |
87 | * @ppos: starting offset in file. | |
88 | * | |
89 | * Userspace wants to read an attribute file. The attribute descriptor | |
90 | * is in the file's ->d_fsdata. The target item is in the directory's | |
91 | * ->d_fsdata. | |
92 | * | |
93 | * We call fill_read_buffer() to allocate and fill the buffer from the | |
94 | * item's show() method exactly once (if the read is happening from | |
95 | * the beginning of the file). That should fill the entire buffer with | |
96 | * all the data the item has to offer for that attribute. | |
97 | * We then call flush_read_buffer() to copy the buffer to userspace | |
98 | * in the increments specified. | |
99 | */ | |
100 | ||
101 | static ssize_t | |
102 | configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
103 | { | |
ff4dd081 | 104 | struct configfs_buffer *buffer = file->private_data; |
7063fbf2 JB |
105 | ssize_t retval = 0; |
106 | ||
6d748924 | 107 | mutex_lock(&buffer->mutex); |
7063fbf2 | 108 | if (buffer->needs_read_fill) { |
b0841eef | 109 | retval = fill_read_buffer(file, buffer); |
ff4dd081 | 110 | if (retval) |
7063fbf2 JB |
111 | goto out; |
112 | } | |
4779efca | 113 | pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n", |
8e24eea7 | 114 | __func__, count, *ppos, buffer->page); |
92f4c701 AM |
115 | retval = simple_read_from_buffer(buf, count, ppos, buffer->page, |
116 | buffer->count); | |
7063fbf2 | 117 | out: |
6d748924 | 118 | mutex_unlock(&buffer->mutex); |
7063fbf2 JB |
119 | return retval; |
120 | } | |
121 | ||
03607ace PA |
122 | /** |
123 | * configfs_read_bin_file - read a binary attribute. | |
124 | * @file: file pointer. | |
125 | * @buf: buffer to fill. | |
126 | * @count: number of bytes to read. | |
127 | * @ppos: starting offset in file. | |
128 | * | |
129 | * Userspace wants to read a binary attribute file. The attribute | |
130 | * descriptor is in the file's ->d_fsdata. The target item is in the | |
131 | * directory's ->d_fsdata. | |
132 | * | |
133 | * We check whether we need to refill the buffer. If so we will | |
134 | * call the attributes' attr->read() twice. The first time we | |
135 | * will pass a NULL as a buffer pointer, which the attributes' method | |
136 | * will use to return the size of the buffer required. If no error | |
137 | * occurs we will allocate the buffer using vmalloc and call | |
138 | * attr->read() again passing that buffer as an argument. | |
139 | * Then we just copy to user-space using simple_read_from_buffer. | |
140 | */ | |
141 | ||
142 | static ssize_t | |
143 | configfs_read_bin_file(struct file *file, char __user *buf, | |
144 | size_t count, loff_t *ppos) | |
145 | { | |
b0841eef | 146 | struct configfs_fragment *frag = to_frag(file); |
03607ace | 147 | struct configfs_buffer *buffer = file->private_data; |
03607ace PA |
148 | ssize_t retval = 0; |
149 | ssize_t len = min_t(size_t, count, PAGE_SIZE); | |
150 | ||
151 | mutex_lock(&buffer->mutex); | |
152 | ||
153 | /* we don't support switching read/write modes */ | |
154 | if (buffer->write_in_progress) { | |
155 | retval = -ETXTBSY; | |
156 | goto out; | |
157 | } | |
3f6928c3 | 158 | buffer->read_in_progress = true; |
03607ace PA |
159 | |
160 | if (buffer->needs_read_fill) { | |
161 | /* perform first read with buf == NULL to get extent */ | |
b0841eef AV |
162 | down_read(&frag->frag_sem); |
163 | if (!frag->frag_dead) | |
164 | len = buffer->bin_attr->read(buffer->item, NULL, 0); | |
165 | else | |
166 | len = -ENOENT; | |
167 | up_read(&frag->frag_sem); | |
03607ace PA |
168 | if (len <= 0) { |
169 | retval = len; | |
170 | goto out; | |
171 | } | |
172 | ||
173 | /* do not exceed the maximum value */ | |
ff4dd081 | 174 | if (buffer->cb_max_size && len > buffer->cb_max_size) { |
03607ace PA |
175 | retval = -EFBIG; |
176 | goto out; | |
177 | } | |
178 | ||
179 | buffer->bin_buffer = vmalloc(len); | |
180 | if (buffer->bin_buffer == NULL) { | |
181 | retval = -ENOMEM; | |
182 | goto out; | |
183 | } | |
184 | buffer->bin_buffer_size = len; | |
185 | ||
186 | /* perform second read to fill buffer */ | |
b0841eef AV |
187 | down_read(&frag->frag_sem); |
188 | if (!frag->frag_dead) | |
189 | len = buffer->bin_attr->read(buffer->item, | |
190 | buffer->bin_buffer, len); | |
191 | else | |
192 | len = -ENOENT; | |
193 | up_read(&frag->frag_sem); | |
03607ace PA |
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 | ||
7063fbf2 | 243 | static int |
b0841eef | 244 | flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t count) |
7063fbf2 | 245 | { |
b0841eef AV |
246 | struct configfs_fragment *frag = to_frag(file); |
247 | int res = -ENOENT; | |
248 | ||
249 | down_read(&frag->frag_sem); | |
250 | if (!frag->frag_dead) | |
251 | res = buffer->attr->store(buffer->item, buffer->page, count); | |
252 | up_read(&frag->frag_sem); | |
253 | return res; | |
7063fbf2 JB |
254 | } |
255 | ||
256 | ||
257 | /** | |
258 | * configfs_write_file - write an attribute. | |
259 | * @file: file pointer | |
260 | * @buf: data to write | |
261 | * @count: number of bytes | |
262 | * @ppos: starting offset | |
263 | * | |
264 | * Similar to configfs_read_file(), though working in the opposite direction. | |
265 | * We allocate and fill the data from the user in fill_write_buffer(), | |
266 | * then push it to the config_item in flush_write_buffer(). | |
267 | * There is no easy way for us to know if userspace is only doing a partial | |
268 | * write, so we don't support them. We expect the entire buffer to come | |
269 | * on the first write. | |
ce9bebe6 | 270 | * Hint: if you're writing a value, first read the file, modify only |
7063fbf2 JB |
271 | * the value you're changing, then write entire buffer back. |
272 | */ | |
273 | ||
274 | static ssize_t | |
275 | configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
276 | { | |
ff4dd081 | 277 | struct configfs_buffer *buffer = file->private_data; |
3d0f89bb | 278 | ssize_t len; |
7063fbf2 | 279 | |
6d748924 | 280 | mutex_lock(&buffer->mutex); |
3d0f89bb JB |
281 | len = fill_write_buffer(buffer, buf, count); |
282 | if (len > 0) | |
b0841eef | 283 | len = flush_write_buffer(file, buffer, len); |
3d0f89bb JB |
284 | if (len > 0) |
285 | *ppos += len; | |
6d748924 | 286 | mutex_unlock(&buffer->mutex); |
3d0f89bb | 287 | return len; |
7063fbf2 JB |
288 | } |
289 | ||
03607ace PA |
290 | /** |
291 | * configfs_write_bin_file - write a binary attribute. | |
292 | * @file: file pointer | |
293 | * @buf: data to write | |
294 | * @count: number of bytes | |
295 | * @ppos: starting offset | |
296 | * | |
297 | * Writing to a binary attribute file is similar to a normal read. | |
298 | * We buffer the consecutive writes (binary attribute files do not | |
299 | * support lseek) in a continuously growing buffer, but we don't | |
300 | * commit until the close of the file. | |
301 | */ | |
302 | ||
303 | static ssize_t | |
304 | configfs_write_bin_file(struct file *file, const char __user *buf, | |
305 | size_t count, loff_t *ppos) | |
306 | { | |
307 | struct configfs_buffer *buffer = file->private_data; | |
03607ace PA |
308 | void *tbuf = NULL; |
309 | ssize_t len; | |
310 | ||
311 | mutex_lock(&buffer->mutex); | |
312 | ||
313 | /* we don't support switching read/write modes */ | |
314 | if (buffer->read_in_progress) { | |
315 | len = -ETXTBSY; | |
316 | goto out; | |
317 | } | |
3f6928c3 | 318 | buffer->write_in_progress = true; |
03607ace PA |
319 | |
320 | /* buffer grows? */ | |
321 | if (*ppos + count > buffer->bin_buffer_size) { | |
322 | ||
ff4dd081 AV |
323 | if (buffer->cb_max_size && |
324 | *ppos + count > buffer->cb_max_size) { | |
03607ace | 325 | len = -EFBIG; |
42857cf5 | 326 | goto out; |
03607ace PA |
327 | } |
328 | ||
329 | tbuf = vmalloc(*ppos + count); | |
330 | if (tbuf == NULL) { | |
331 | len = -ENOMEM; | |
332 | goto out; | |
333 | } | |
334 | ||
335 | /* copy old contents */ | |
336 | if (buffer->bin_buffer) { | |
337 | memcpy(tbuf, buffer->bin_buffer, | |
338 | buffer->bin_buffer_size); | |
339 | vfree(buffer->bin_buffer); | |
340 | } | |
341 | ||
342 | /* clear the new area */ | |
343 | memset(tbuf + buffer->bin_buffer_size, 0, | |
344 | *ppos + count - buffer->bin_buffer_size); | |
345 | buffer->bin_buffer = tbuf; | |
346 | buffer->bin_buffer_size = *ppos + count; | |
347 | } | |
348 | ||
349 | len = simple_write_to_buffer(buffer->bin_buffer, | |
350 | buffer->bin_buffer_size, ppos, buf, count); | |
03607ace PA |
351 | out: |
352 | mutex_unlock(&buffer->mutex); | |
353 | return len; | |
354 | } | |
355 | ||
ff4dd081 | 356 | static int __configfs_open_file(struct inode *inode, struct file *file, int type) |
7063fbf2 | 357 | { |
ff4dd081 | 358 | struct dentry *dentry = file->f_path.dentry; |
b0841eef | 359 | struct configfs_fragment *frag = to_frag(file); |
ff4dd081 AV |
360 | struct configfs_attribute *attr; |
361 | struct configfs_buffer *buffer; | |
362 | int error; | |
7063fbf2 | 363 | |
ff4dd081 AV |
364 | error = -ENOMEM; |
365 | buffer = kzalloc(sizeof(struct configfs_buffer), GFP_KERNEL); | |
366 | if (!buffer) | |
367 | goto out; | |
7063fbf2 | 368 | |
b0841eef AV |
369 | error = -ENOENT; |
370 | down_read(&frag->frag_sem); | |
371 | if (unlikely(frag->frag_dead)) | |
372 | goto out_free_buffer; | |
373 | ||
ff4dd081 | 374 | error = -EINVAL; |
b0841eef | 375 | buffer->item = to_item(dentry->d_parent); |
ff4dd081 AV |
376 | if (!buffer->item) |
377 | goto out_free_buffer; | |
378 | ||
379 | attr = to_attr(dentry); | |
380 | if (!attr) | |
381 | goto out_put_item; | |
382 | ||
383 | if (type & CONFIGFS_ITEM_BIN_ATTR) { | |
384 | buffer->bin_attr = to_bin_attr(dentry); | |
385 | buffer->cb_max_size = buffer->bin_attr->cb_max_size; | |
386 | } else { | |
387 | buffer->attr = attr; | |
388 | } | |
03607ace | 389 | |
ff4dd081 | 390 | buffer->owner = attr->ca_owner; |
7063fbf2 | 391 | /* Grab the module reference for this attribute if we have one */ |
ff4dd081 AV |
392 | error = -ENODEV; |
393 | if (!try_module_get(buffer->owner)) | |
394 | goto out_put_item; | |
7063fbf2 | 395 | |
ff4dd081 AV |
396 | error = -EACCES; |
397 | if (!buffer->item->ci_type) | |
398 | goto out_put_module; | |
399 | ||
400 | buffer->ops = buffer->item->ci_type->ct_item_ops; | |
7063fbf2 JB |
401 | |
402 | /* File needs write support. | |
403 | * The inode's perms must say it's ok, | |
404 | * and we must have a store method. | |
405 | */ | |
406 | if (file->f_mode & FMODE_WRITE) { | |
03607ace | 407 | if (!(inode->i_mode & S_IWUGO)) |
ff4dd081 | 408 | goto out_put_module; |
03607ace | 409 | if ((type & CONFIGFS_ITEM_ATTR) && !attr->store) |
ff4dd081 AV |
410 | goto out_put_module; |
411 | if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->write) | |
412 | goto out_put_module; | |
7063fbf2 JB |
413 | } |
414 | ||
415 | /* File needs read support. | |
416 | * The inode's perms must say it's ok, and we there | |
417 | * must be a show method for it. | |
418 | */ | |
419 | if (file->f_mode & FMODE_READ) { | |
03607ace | 420 | if (!(inode->i_mode & S_IRUGO)) |
ff4dd081 | 421 | goto out_put_module; |
03607ace | 422 | if ((type & CONFIGFS_ITEM_ATTR) && !attr->show) |
ff4dd081 AV |
423 | goto out_put_module; |
424 | if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->read) | |
425 | goto out_put_module; | |
7063fbf2 JB |
426 | } |
427 | ||
6d748924 | 428 | mutex_init(&buffer->mutex); |
559c9ac3 | 429 | buffer->needs_read_fill = 1; |
3f6928c3 TM |
430 | buffer->read_in_progress = false; |
431 | buffer->write_in_progress = false; | |
559c9ac3 | 432 | file->private_data = buffer; |
b0841eef | 433 | up_read(&frag->frag_sem); |
ff4dd081 | 434 | return 0; |
7063fbf2 | 435 | |
ff4dd081 AV |
436 | out_put_module: |
437 | module_put(buffer->owner); | |
438 | out_put_item: | |
439 | config_item_put(buffer->item); | |
440 | out_free_buffer: | |
b0841eef | 441 | up_read(&frag->frag_sem); |
ff4dd081 AV |
442 | kfree(buffer); |
443 | out: | |
7063fbf2 JB |
444 | return error; |
445 | } | |
446 | ||
03607ace | 447 | static int configfs_release(struct inode *inode, struct file *filp) |
7063fbf2 | 448 | { |
ff4dd081 AV |
449 | struct configfs_buffer *buffer = filp->private_data; |
450 | ||
ff4dd081 AV |
451 | module_put(buffer->owner); |
452 | if (buffer->page) | |
453 | free_page((unsigned long)buffer->page); | |
454 | mutex_destroy(&buffer->mutex); | |
455 | kfree(buffer); | |
7063fbf2 JB |
456 | return 0; |
457 | } | |
458 | ||
03607ace PA |
459 | static int configfs_open_file(struct inode *inode, struct file *filp) |
460 | { | |
ff4dd081 | 461 | return __configfs_open_file(inode, filp, CONFIGFS_ITEM_ATTR); |
03607ace PA |
462 | } |
463 | ||
464 | static int configfs_open_bin_file(struct inode *inode, struct file *filp) | |
465 | { | |
ff4dd081 | 466 | return __configfs_open_file(inode, filp, CONFIGFS_ITEM_BIN_ATTR); |
03607ace PA |
467 | } |
468 | ||
ff4dd081 | 469 | static int configfs_release_bin_file(struct inode *inode, struct file *file) |
03607ace | 470 | { |
ff4dd081 | 471 | struct configfs_buffer *buffer = file->private_data; |
03607ace | 472 | |
3f6928c3 | 473 | buffer->read_in_progress = false; |
03607ace PA |
474 | |
475 | if (buffer->write_in_progress) { | |
b0841eef | 476 | struct configfs_fragment *frag = to_frag(file); |
3f6928c3 | 477 | buffer->write_in_progress = false; |
03607ace | 478 | |
b0841eef AV |
479 | down_read(&frag->frag_sem); |
480 | if (!frag->frag_dead) { | |
481 | /* result of ->release() is ignored */ | |
482 | buffer->bin_attr->write(buffer->item, | |
483 | buffer->bin_buffer, | |
484 | buffer->bin_buffer_size); | |
485 | } | |
486 | up_read(&frag->frag_sem); | |
03607ace PA |
487 | /* vfree on NULL is safe */ |
488 | vfree(buffer->bin_buffer); | |
489 | buffer->bin_buffer = NULL; | |
490 | buffer->bin_buffer_size = 0; | |
491 | buffer->needs_read_fill = 1; | |
492 | } | |
493 | ||
ff4dd081 AV |
494 | configfs_release(inode, file); |
495 | return 0; | |
03607ace PA |
496 | } |
497 | ||
498 | ||
4b6f5d20 | 499 | const struct file_operations configfs_file_operations = { |
7063fbf2 JB |
500 | .read = configfs_read_file, |
501 | .write = configfs_write_file, | |
502 | .llseek = generic_file_llseek, | |
503 | .open = configfs_open_file, | |
504 | .release = configfs_release, | |
505 | }; | |
506 | ||
03607ace PA |
507 | const struct file_operations configfs_bin_file_operations = { |
508 | .read = configfs_read_bin_file, | |
509 | .write = configfs_write_bin_file, | |
510 | .llseek = NULL, /* bin file is not seekable */ | |
511 | .open = configfs_open_bin_file, | |
512 | .release = configfs_release_bin_file, | |
513 | }; | |
514 | ||
7063fbf2 JB |
515 | /** |
516 | * configfs_create_file - create an attribute file for an item. | |
517 | * @item: item we're creating for. | |
518 | * @attr: atrribute descriptor. | |
519 | */ | |
520 | ||
521 | int configfs_create_file(struct config_item * item, const struct configfs_attribute * attr) | |
522 | { | |
28444a2b AV |
523 | struct dentry *dir = item->ci_dentry; |
524 | struct configfs_dirent *parent_sd = dir->d_fsdata; | |
525 | umode_t mode = (attr->ca_mode & S_IALLUGO) | S_IFREG; | |
526 | int error = 0; | |
7063fbf2 | 527 | |
5955102c | 528 | inode_lock_nested(d_inode(dir), I_MUTEX_NORMAL); |
28444a2b | 529 | error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode, |
47320fbe | 530 | CONFIGFS_ITEM_ATTR, parent_sd->s_frag); |
5955102c | 531 | inode_unlock(d_inode(dir)); |
28444a2b AV |
532 | |
533 | return error; | |
7063fbf2 JB |
534 | } |
535 | ||
03607ace PA |
536 | /** |
537 | * configfs_create_bin_file - create a binary attribute file for an item. | |
538 | * @item: item we're creating for. | |
539 | * @attr: atrribute descriptor. | |
540 | */ | |
541 | ||
542 | int configfs_create_bin_file(struct config_item *item, | |
543 | const struct configfs_bin_attribute *bin_attr) | |
544 | { | |
545 | struct dentry *dir = item->ci_dentry; | |
546 | struct configfs_dirent *parent_sd = dir->d_fsdata; | |
547 | umode_t mode = (bin_attr->cb_attr.ca_mode & S_IALLUGO) | S_IFREG; | |
548 | int error = 0; | |
549 | ||
5955102c | 550 | inode_lock_nested(dir->d_inode, I_MUTEX_NORMAL); |
03607ace | 551 | error = configfs_make_dirent(parent_sd, NULL, (void *) bin_attr, mode, |
47320fbe | 552 | CONFIGFS_ITEM_BIN_ATTR, parent_sd->s_frag); |
5955102c | 553 | inode_unlock(dir->d_inode); |
03607ace PA |
554 | |
555 | return error; | |
556 | } |