Commit | Line | Data |
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328970de | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
fa60ce2c | 2 | /* |
7063fbf2 JB |
3 | * file.c - operations for regular (text) files. |
4 | * | |
7063fbf2 JB |
5 | * Based on sysfs: |
6 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel | |
7 | * | |
8 | * configfs Copyright (C) 2005 Oracle. All rights reserved. | |
9 | */ | |
10 | ||
11 | #include <linux/fs.h> | |
12 | #include <linux/module.h> | |
7063fbf2 | 13 | #include <linux/slab.h> |
6d748924 | 14 | #include <linux/mutex.h> |
03607ace | 15 | #include <linux/vmalloc.h> |
7c0f6ba6 | 16 | #include <linux/uaccess.h> |
7063fbf2 JB |
17 | |
18 | #include <linux/configfs.h> | |
19 | #include "configfs_internal.h" | |
20 | ||
b23cdde4 JB |
21 | /* |
22 | * A simple attribute can only be 4096 characters. Why 4k? Because the | |
23 | * original code limited it to PAGE_SIZE. That's a bad idea, though, | |
24 | * because an attribute of 16k on ia64 won't work on x86. So we limit to | |
25 | * 4k, our minimum common page size. | |
26 | */ | |
27 | #define SIMPLE_ATTR_SIZE 4096 | |
7063fbf2 JB |
28 | |
29 | struct configfs_buffer { | |
30 | size_t count; | |
31 | loff_t pos; | |
32 | char * page; | |
33 | struct configfs_item_operations * ops; | |
6d748924 | 34 | struct mutex mutex; |
7063fbf2 | 35 | int needs_read_fill; |
03607ace PA |
36 | bool read_in_progress; |
37 | bool write_in_progress; | |
38 | char *bin_buffer; | |
39 | int bin_buffer_size; | |
ff4dd081 AV |
40 | int cb_max_size; |
41 | struct config_item *item; | |
42 | struct module *owner; | |
43 | union { | |
44 | struct configfs_attribute *attr; | |
45 | struct configfs_bin_attribute *bin_attr; | |
46 | }; | |
7063fbf2 JB |
47 | }; |
48 | ||
b0841eef AV |
49 | static inline struct configfs_fragment *to_frag(struct file *file) |
50 | { | |
51 | struct configfs_dirent *sd = file->f_path.dentry->d_fsdata; | |
52 | ||
53 | return sd->s_frag; | |
54 | } | |
7063fbf2 | 55 | |
b0841eef | 56 | static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer) |
7063fbf2 | 57 | { |
b0841eef AV |
58 | struct configfs_fragment *frag = to_frag(file); |
59 | ssize_t count = -ENOENT; | |
7063fbf2 JB |
60 | |
61 | if (!buffer->page) | |
62 | buffer->page = (char *) get_zeroed_page(GFP_KERNEL); | |
63 | if (!buffer->page) | |
64 | return -ENOMEM; | |
65 | ||
b0841eef AV |
66 | down_read(&frag->frag_sem); |
67 | if (!frag->frag_dead) | |
68 | count = buffer->attr->show(buffer->item, buffer->page); | |
69 | up_read(&frag->frag_sem); | |
70 | ||
ff4dd081 AV |
71 | if (count < 0) |
72 | return count; | |
73 | if (WARN_ON_ONCE(count > (ssize_t)SIMPLE_ATTR_SIZE)) | |
74 | return -EIO; | |
ff4dd081 AV |
75 | buffer->needs_read_fill = 0; |
76 | buffer->count = count; | |
77 | return 0; | |
7063fbf2 JB |
78 | } |
79 | ||
7063fbf2 JB |
80 | /** |
81 | * configfs_read_file - read an attribute. | |
82 | * @file: file pointer. | |
83 | * @buf: buffer to fill. | |
84 | * @count: number of bytes to read. | |
85 | * @ppos: starting offset in file. | |
86 | * | |
87 | * Userspace wants to read an attribute file. The attribute descriptor | |
88 | * is in the file's ->d_fsdata. The target item is in the directory's | |
89 | * ->d_fsdata. | |
90 | * | |
91 | * We call fill_read_buffer() to allocate and fill the buffer from the | |
92 | * item's show() method exactly once (if the read is happening from | |
93 | * the beginning of the file). That should fill the entire buffer with | |
94 | * all the data the item has to offer for that attribute. | |
95 | * We then call flush_read_buffer() to copy the buffer to userspace | |
96 | * in the increments specified. | |
97 | */ | |
98 | ||
99 | static ssize_t | |
100 | configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
101 | { | |
ff4dd081 | 102 | struct configfs_buffer *buffer = file->private_data; |
7063fbf2 JB |
103 | ssize_t retval = 0; |
104 | ||
6d748924 | 105 | mutex_lock(&buffer->mutex); |
7063fbf2 | 106 | if (buffer->needs_read_fill) { |
b0841eef | 107 | retval = fill_read_buffer(file, buffer); |
ff4dd081 | 108 | if (retval) |
7063fbf2 JB |
109 | goto out; |
110 | } | |
4779efca | 111 | pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n", |
8e24eea7 | 112 | __func__, count, *ppos, buffer->page); |
92f4c701 AM |
113 | retval = simple_read_from_buffer(buf, count, ppos, buffer->page, |
114 | buffer->count); | |
7063fbf2 | 115 | out: |
6d748924 | 116 | mutex_unlock(&buffer->mutex); |
7063fbf2 JB |
117 | return retval; |
118 | } | |
119 | ||
03607ace PA |
120 | /** |
121 | * configfs_read_bin_file - read a binary attribute. | |
122 | * @file: file pointer. | |
123 | * @buf: buffer to fill. | |
124 | * @count: number of bytes to read. | |
125 | * @ppos: starting offset in file. | |
126 | * | |
127 | * Userspace wants to read a binary attribute file. The attribute | |
128 | * descriptor is in the file's ->d_fsdata. The target item is in the | |
129 | * directory's ->d_fsdata. | |
130 | * | |
131 | * We check whether we need to refill the buffer. If so we will | |
132 | * call the attributes' attr->read() twice. The first time we | |
133 | * will pass a NULL as a buffer pointer, which the attributes' method | |
134 | * will use to return the size of the buffer required. If no error | |
135 | * occurs we will allocate the buffer using vmalloc and call | |
136 | * attr->read() again passing that buffer as an argument. | |
137 | * Then we just copy to user-space using simple_read_from_buffer. | |
138 | */ | |
139 | ||
140 | static ssize_t | |
141 | configfs_read_bin_file(struct file *file, char __user *buf, | |
142 | size_t count, loff_t *ppos) | |
143 | { | |
b0841eef | 144 | struct configfs_fragment *frag = to_frag(file); |
03607ace | 145 | struct configfs_buffer *buffer = file->private_data; |
03607ace PA |
146 | ssize_t retval = 0; |
147 | ssize_t len = min_t(size_t, count, PAGE_SIZE); | |
148 | ||
149 | mutex_lock(&buffer->mutex); | |
150 | ||
151 | /* we don't support switching read/write modes */ | |
152 | if (buffer->write_in_progress) { | |
153 | retval = -ETXTBSY; | |
154 | goto out; | |
155 | } | |
3f6928c3 | 156 | buffer->read_in_progress = true; |
03607ace PA |
157 | |
158 | if (buffer->needs_read_fill) { | |
159 | /* perform first read with buf == NULL to get extent */ | |
b0841eef AV |
160 | down_read(&frag->frag_sem); |
161 | if (!frag->frag_dead) | |
162 | len = buffer->bin_attr->read(buffer->item, NULL, 0); | |
163 | else | |
164 | len = -ENOENT; | |
165 | up_read(&frag->frag_sem); | |
03607ace PA |
166 | if (len <= 0) { |
167 | retval = len; | |
168 | goto out; | |
169 | } | |
170 | ||
171 | /* do not exceed the maximum value */ | |
ff4dd081 | 172 | if (buffer->cb_max_size && len > buffer->cb_max_size) { |
03607ace PA |
173 | retval = -EFBIG; |
174 | goto out; | |
175 | } | |
176 | ||
177 | buffer->bin_buffer = vmalloc(len); | |
178 | if (buffer->bin_buffer == NULL) { | |
179 | retval = -ENOMEM; | |
180 | goto out; | |
181 | } | |
182 | buffer->bin_buffer_size = len; | |
183 | ||
184 | /* perform second read to fill buffer */ | |
b0841eef AV |
185 | down_read(&frag->frag_sem); |
186 | if (!frag->frag_dead) | |
187 | len = buffer->bin_attr->read(buffer->item, | |
188 | buffer->bin_buffer, len); | |
189 | else | |
190 | len = -ENOENT; | |
191 | up_read(&frag->frag_sem); | |
03607ace PA |
192 | if (len < 0) { |
193 | retval = len; | |
194 | vfree(buffer->bin_buffer); | |
195 | buffer->bin_buffer_size = 0; | |
196 | buffer->bin_buffer = NULL; | |
197 | goto out; | |
198 | } | |
199 | ||
200 | buffer->needs_read_fill = 0; | |
201 | } | |
202 | ||
203 | retval = simple_read_from_buffer(buf, count, ppos, buffer->bin_buffer, | |
204 | buffer->bin_buffer_size); | |
205 | out: | |
206 | mutex_unlock(&buffer->mutex); | |
207 | return retval; | |
208 | } | |
209 | ||
7063fbf2 JB |
210 | |
211 | /** | |
212 | * fill_write_buffer - copy buffer from userspace. | |
213 | * @buffer: data buffer for file. | |
3d0f89bb | 214 | * @buf: data from user. |
7063fbf2 JB |
215 | * @count: number of bytes in @userbuf. |
216 | * | |
217 | * Allocate @buffer->page if it hasn't been already, then | |
218 | * copy the user-supplied buffer into it. | |
219 | */ | |
220 | ||
221 | static int | |
222 | fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size_t count) | |
223 | { | |
224 | int error; | |
225 | ||
226 | if (!buffer->page) | |
ff05d1c4 | 227 | buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0); |
7063fbf2 JB |
228 | if (!buffer->page) |
229 | return -ENOMEM; | |
230 | ||
b23cdde4 JB |
231 | if (count >= SIMPLE_ATTR_SIZE) |
232 | count = SIMPLE_ATTR_SIZE - 1; | |
7063fbf2 JB |
233 | error = copy_from_user(buffer->page,buf,count); |
234 | buffer->needs_read_fill = 1; | |
ff05d1c4 JB |
235 | /* if buf is assumed to contain a string, terminate it by \0, |
236 | * so e.g. sscanf() can scan the string easily */ | |
237 | buffer->page[count] = 0; | |
7063fbf2 JB |
238 | return error ? -EFAULT : count; |
239 | } | |
240 | ||
7063fbf2 | 241 | static int |
b0841eef | 242 | flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t count) |
7063fbf2 | 243 | { |
b0841eef AV |
244 | struct configfs_fragment *frag = to_frag(file); |
245 | int res = -ENOENT; | |
246 | ||
247 | down_read(&frag->frag_sem); | |
248 | if (!frag->frag_dead) | |
249 | res = buffer->attr->store(buffer->item, buffer->page, count); | |
250 | up_read(&frag->frag_sem); | |
251 | return res; | |
7063fbf2 JB |
252 | } |
253 | ||
254 | ||
255 | /** | |
256 | * configfs_write_file - write an attribute. | |
257 | * @file: file pointer | |
258 | * @buf: data to write | |
259 | * @count: number of bytes | |
260 | * @ppos: starting offset | |
261 | * | |
262 | * Similar to configfs_read_file(), though working in the opposite direction. | |
263 | * We allocate and fill the data from the user in fill_write_buffer(), | |
264 | * then push it to the config_item in flush_write_buffer(). | |
265 | * There is no easy way for us to know if userspace is only doing a partial | |
266 | * write, so we don't support them. We expect the entire buffer to come | |
267 | * on the first write. | |
ce9bebe6 | 268 | * Hint: if you're writing a value, first read the file, modify only |
7063fbf2 JB |
269 | * the value you're changing, then write entire buffer back. |
270 | */ | |
271 | ||
272 | static ssize_t | |
273 | configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
274 | { | |
ff4dd081 | 275 | struct configfs_buffer *buffer = file->private_data; |
3d0f89bb | 276 | ssize_t len; |
7063fbf2 | 277 | |
6d748924 | 278 | mutex_lock(&buffer->mutex); |
3d0f89bb JB |
279 | len = fill_write_buffer(buffer, buf, count); |
280 | if (len > 0) | |
b0841eef | 281 | len = flush_write_buffer(file, buffer, len); |
3d0f89bb JB |
282 | if (len > 0) |
283 | *ppos += len; | |
6d748924 | 284 | mutex_unlock(&buffer->mutex); |
3d0f89bb | 285 | return len; |
7063fbf2 JB |
286 | } |
287 | ||
03607ace PA |
288 | /** |
289 | * configfs_write_bin_file - write a binary attribute. | |
290 | * @file: file pointer | |
291 | * @buf: data to write | |
292 | * @count: number of bytes | |
293 | * @ppos: starting offset | |
294 | * | |
295 | * Writing to a binary attribute file is similar to a normal read. | |
296 | * We buffer the consecutive writes (binary attribute files do not | |
297 | * support lseek) in a continuously growing buffer, but we don't | |
298 | * commit until the close of the file. | |
299 | */ | |
300 | ||
301 | static ssize_t | |
302 | configfs_write_bin_file(struct file *file, const char __user *buf, | |
303 | size_t count, loff_t *ppos) | |
304 | { | |
305 | struct configfs_buffer *buffer = file->private_data; | |
03607ace PA |
306 | void *tbuf = NULL; |
307 | ssize_t len; | |
308 | ||
309 | mutex_lock(&buffer->mutex); | |
310 | ||
311 | /* we don't support switching read/write modes */ | |
312 | if (buffer->read_in_progress) { | |
313 | len = -ETXTBSY; | |
314 | goto out; | |
315 | } | |
3f6928c3 | 316 | buffer->write_in_progress = true; |
03607ace PA |
317 | |
318 | /* buffer grows? */ | |
319 | if (*ppos + count > buffer->bin_buffer_size) { | |
320 | ||
ff4dd081 AV |
321 | if (buffer->cb_max_size && |
322 | *ppos + count > buffer->cb_max_size) { | |
03607ace | 323 | len = -EFBIG; |
42857cf5 | 324 | goto out; |
03607ace PA |
325 | } |
326 | ||
327 | tbuf = vmalloc(*ppos + count); | |
328 | if (tbuf == NULL) { | |
329 | len = -ENOMEM; | |
330 | goto out; | |
331 | } | |
332 | ||
333 | /* copy old contents */ | |
334 | if (buffer->bin_buffer) { | |
335 | memcpy(tbuf, buffer->bin_buffer, | |
336 | buffer->bin_buffer_size); | |
337 | vfree(buffer->bin_buffer); | |
338 | } | |
339 | ||
340 | /* clear the new area */ | |
341 | memset(tbuf + buffer->bin_buffer_size, 0, | |
342 | *ppos + count - buffer->bin_buffer_size); | |
343 | buffer->bin_buffer = tbuf; | |
344 | buffer->bin_buffer_size = *ppos + count; | |
345 | } | |
346 | ||
347 | len = simple_write_to_buffer(buffer->bin_buffer, | |
348 | buffer->bin_buffer_size, ppos, buf, count); | |
03607ace PA |
349 | out: |
350 | mutex_unlock(&buffer->mutex); | |
351 | return len; | |
352 | } | |
353 | ||
ff4dd081 | 354 | static int __configfs_open_file(struct inode *inode, struct file *file, int type) |
7063fbf2 | 355 | { |
ff4dd081 | 356 | struct dentry *dentry = file->f_path.dentry; |
b0841eef | 357 | struct configfs_fragment *frag = to_frag(file); |
ff4dd081 AV |
358 | struct configfs_attribute *attr; |
359 | struct configfs_buffer *buffer; | |
360 | int error; | |
7063fbf2 | 361 | |
ff4dd081 AV |
362 | error = -ENOMEM; |
363 | buffer = kzalloc(sizeof(struct configfs_buffer), GFP_KERNEL); | |
364 | if (!buffer) | |
365 | goto out; | |
7063fbf2 | 366 | |
b0841eef AV |
367 | error = -ENOENT; |
368 | down_read(&frag->frag_sem); | |
369 | if (unlikely(frag->frag_dead)) | |
370 | goto out_free_buffer; | |
371 | ||
ff4dd081 | 372 | error = -EINVAL; |
b0841eef | 373 | buffer->item = to_item(dentry->d_parent); |
ff4dd081 AV |
374 | if (!buffer->item) |
375 | goto out_free_buffer; | |
376 | ||
377 | attr = to_attr(dentry); | |
378 | if (!attr) | |
14fbbc82 | 379 | goto out_free_buffer; |
ff4dd081 AV |
380 | |
381 | if (type & CONFIGFS_ITEM_BIN_ATTR) { | |
382 | buffer->bin_attr = to_bin_attr(dentry); | |
383 | buffer->cb_max_size = buffer->bin_attr->cb_max_size; | |
384 | } else { | |
385 | buffer->attr = attr; | |
386 | } | |
03607ace | 387 | |
ff4dd081 | 388 | buffer->owner = attr->ca_owner; |
7063fbf2 | 389 | /* Grab the module reference for this attribute if we have one */ |
ff4dd081 AV |
390 | error = -ENODEV; |
391 | if (!try_module_get(buffer->owner)) | |
14fbbc82 | 392 | goto out_free_buffer; |
7063fbf2 | 393 | |
ff4dd081 AV |
394 | error = -EACCES; |
395 | if (!buffer->item->ci_type) | |
396 | goto out_put_module; | |
397 | ||
398 | buffer->ops = buffer->item->ci_type->ct_item_ops; | |
7063fbf2 JB |
399 | |
400 | /* File needs write support. | |
401 | * The inode's perms must say it's ok, | |
402 | * and we must have a store method. | |
403 | */ | |
404 | if (file->f_mode & FMODE_WRITE) { | |
03607ace | 405 | if (!(inode->i_mode & S_IWUGO)) |
ff4dd081 | 406 | goto out_put_module; |
03607ace | 407 | if ((type & CONFIGFS_ITEM_ATTR) && !attr->store) |
ff4dd081 AV |
408 | goto out_put_module; |
409 | if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->write) | |
410 | goto out_put_module; | |
7063fbf2 JB |
411 | } |
412 | ||
413 | /* File needs read support. | |
414 | * The inode's perms must say it's ok, and we there | |
415 | * must be a show method for it. | |
416 | */ | |
417 | if (file->f_mode & FMODE_READ) { | |
03607ace | 418 | if (!(inode->i_mode & S_IRUGO)) |
ff4dd081 | 419 | goto out_put_module; |
03607ace | 420 | if ((type & CONFIGFS_ITEM_ATTR) && !attr->show) |
ff4dd081 AV |
421 | goto out_put_module; |
422 | if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->read) | |
423 | goto out_put_module; | |
7063fbf2 JB |
424 | } |
425 | ||
6d748924 | 426 | mutex_init(&buffer->mutex); |
559c9ac3 | 427 | buffer->needs_read_fill = 1; |
3f6928c3 TM |
428 | buffer->read_in_progress = false; |
429 | buffer->write_in_progress = false; | |
559c9ac3 | 430 | file->private_data = buffer; |
b0841eef | 431 | up_read(&frag->frag_sem); |
ff4dd081 | 432 | return 0; |
7063fbf2 | 433 | |
ff4dd081 AV |
434 | out_put_module: |
435 | module_put(buffer->owner); | |
ff4dd081 | 436 | out_free_buffer: |
b0841eef | 437 | up_read(&frag->frag_sem); |
ff4dd081 AV |
438 | kfree(buffer); |
439 | out: | |
7063fbf2 JB |
440 | return error; |
441 | } | |
442 | ||
03607ace | 443 | static int configfs_release(struct inode *inode, struct file *filp) |
7063fbf2 | 444 | { |
ff4dd081 AV |
445 | struct configfs_buffer *buffer = filp->private_data; |
446 | ||
ff4dd081 AV |
447 | module_put(buffer->owner); |
448 | if (buffer->page) | |
449 | free_page((unsigned long)buffer->page); | |
450 | mutex_destroy(&buffer->mutex); | |
451 | kfree(buffer); | |
7063fbf2 JB |
452 | return 0; |
453 | } | |
454 | ||
03607ace PA |
455 | static int configfs_open_file(struct inode *inode, struct file *filp) |
456 | { | |
ff4dd081 | 457 | return __configfs_open_file(inode, filp, CONFIGFS_ITEM_ATTR); |
03607ace PA |
458 | } |
459 | ||
460 | static int configfs_open_bin_file(struct inode *inode, struct file *filp) | |
461 | { | |
ff4dd081 | 462 | return __configfs_open_file(inode, filp, CONFIGFS_ITEM_BIN_ATTR); |
03607ace PA |
463 | } |
464 | ||
ff4dd081 | 465 | static int configfs_release_bin_file(struct inode *inode, struct file *file) |
03607ace | 466 | { |
ff4dd081 | 467 | struct configfs_buffer *buffer = file->private_data; |
03607ace | 468 | |
3f6928c3 | 469 | buffer->read_in_progress = false; |
03607ace PA |
470 | |
471 | if (buffer->write_in_progress) { | |
b0841eef | 472 | struct configfs_fragment *frag = to_frag(file); |
3f6928c3 | 473 | buffer->write_in_progress = false; |
03607ace | 474 | |
b0841eef AV |
475 | down_read(&frag->frag_sem); |
476 | if (!frag->frag_dead) { | |
477 | /* result of ->release() is ignored */ | |
478 | buffer->bin_attr->write(buffer->item, | |
479 | buffer->bin_buffer, | |
480 | buffer->bin_buffer_size); | |
481 | } | |
482 | up_read(&frag->frag_sem); | |
03607ace PA |
483 | /* vfree on NULL is safe */ |
484 | vfree(buffer->bin_buffer); | |
485 | buffer->bin_buffer = NULL; | |
486 | buffer->bin_buffer_size = 0; | |
487 | buffer->needs_read_fill = 1; | |
488 | } | |
489 | ||
ff4dd081 AV |
490 | configfs_release(inode, file); |
491 | return 0; | |
03607ace PA |
492 | } |
493 | ||
494 | ||
4b6f5d20 | 495 | const struct file_operations configfs_file_operations = { |
7063fbf2 JB |
496 | .read = configfs_read_file, |
497 | .write = configfs_write_file, | |
498 | .llseek = generic_file_llseek, | |
499 | .open = configfs_open_file, | |
500 | .release = configfs_release, | |
501 | }; | |
502 | ||
03607ace PA |
503 | const struct file_operations configfs_bin_file_operations = { |
504 | .read = configfs_read_bin_file, | |
505 | .write = configfs_write_bin_file, | |
506 | .llseek = NULL, /* bin file is not seekable */ | |
507 | .open = configfs_open_bin_file, | |
508 | .release = configfs_release_bin_file, | |
509 | }; | |
510 | ||
7063fbf2 JB |
511 | /** |
512 | * configfs_create_file - create an attribute file for an item. | |
513 | * @item: item we're creating for. | |
514 | * @attr: atrribute descriptor. | |
515 | */ | |
516 | ||
517 | int configfs_create_file(struct config_item * item, const struct configfs_attribute * attr) | |
518 | { | |
28444a2b AV |
519 | struct dentry *dir = item->ci_dentry; |
520 | struct configfs_dirent *parent_sd = dir->d_fsdata; | |
521 | umode_t mode = (attr->ca_mode & S_IALLUGO) | S_IFREG; | |
522 | int error = 0; | |
7063fbf2 | 523 | |
5955102c | 524 | inode_lock_nested(d_inode(dir), I_MUTEX_NORMAL); |
28444a2b | 525 | error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode, |
47320fbe | 526 | CONFIGFS_ITEM_ATTR, parent_sd->s_frag); |
5955102c | 527 | inode_unlock(d_inode(dir)); |
28444a2b AV |
528 | |
529 | return error; | |
7063fbf2 JB |
530 | } |
531 | ||
03607ace PA |
532 | /** |
533 | * configfs_create_bin_file - create a binary attribute file for an item. | |
534 | * @item: item we're creating for. | |
535 | * @attr: atrribute descriptor. | |
536 | */ | |
537 | ||
538 | int configfs_create_bin_file(struct config_item *item, | |
539 | const struct configfs_bin_attribute *bin_attr) | |
540 | { | |
541 | struct dentry *dir = item->ci_dentry; | |
542 | struct configfs_dirent *parent_sd = dir->d_fsdata; | |
543 | umode_t mode = (bin_attr->cb_attr.ca_mode & S_IALLUGO) | S_IFREG; | |
544 | int error = 0; | |
545 | ||
5955102c | 546 | inode_lock_nested(dir->d_inode, I_MUTEX_NORMAL); |
03607ace | 547 | error = configfs_make_dirent(parent_sd, NULL, (void *) bin_attr, mode, |
47320fbe | 548 | CONFIGFS_ITEM_BIN_ATTR, parent_sd->s_frag); |
5955102c | 549 | inode_unlock(dir->d_inode); |
03607ace PA |
550 | |
551 | return error; | |
552 | } |