blob: 33b7ee34eda5f135fef480f0bdf55bb4037ab334 [file] [log] [blame]
Joel Becker7063fbf2005-12-15 14:29:43 -08001/* -*- 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>
Joel Becker7063fbf2005-12-15 14:29:43 -080029#include <linux/slab.h>
Johannes Berg6d748922007-06-22 11:20:00 +020030#include <linux/mutex.h>
Pantelis Antoniou03607ac2015-10-22 23:30:04 +030031#include <linux/vmalloc.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080032#include <asm/uaccess.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080033
34#include <linux/configfs.h>
35#include "configfs_internal.h"
36
Joel Beckerb23cdde2007-06-22 13:07:02 -070037/*
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
Joel Becker7063fbf2005-12-15 14:29:43 -080044
45struct configfs_buffer {
46 size_t count;
47 loff_t pos;
48 char * page;
49 struct configfs_item_operations * ops;
Johannes Berg6d748922007-06-22 11:20:00 +020050 struct mutex mutex;
Joel Becker7063fbf2005-12-15 14:29:43 -080051 int needs_read_fill;
Pantelis Antoniou03607ac2015-10-22 23:30:04 +030052 bool read_in_progress;
53 bool write_in_progress;
54 char *bin_buffer;
55 int bin_buffer_size;
Joel Becker7063fbf2005-12-15 14:29:43 -080056};
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 */
69static 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);
Joel Becker7063fbf2005-12-15 14:29:43 -080073 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
Christoph Hellwig51798222015-10-03 15:32:59 +020081 count = attr->show(item, buffer->page);
Christoph Hellwig870823e2015-10-03 15:32:37 +020082
Joel Becker7063fbf2005-12-15 14:29:43 -080083 buffer->needs_read_fill = 0;
Joel Beckerb23cdde2007-06-22 13:07:02 -070084 BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE);
Joel Becker7063fbf2005-12-15 14:29:43 -080085 if (count >= 0)
86 buffer->count = count;
87 else
88 ret = count;
89 return ret;
90}
91
Joel Becker7063fbf2005-12-15 14:29:43 -080092/**
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
111static ssize_t
112configfs_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
Johannes Berg6d748922007-06-22 11:20:00 +0200117 mutex_lock(&buffer->mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800118 if (buffer->needs_read_fill) {
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -0800119 if ((retval = fill_read_buffer(file->f_path.dentry,buffer)))
Joel Becker7063fbf2005-12-15 14:29:43 -0800120 goto out;
121 }
Zach Brown4779efc2006-10-03 01:16:05 -0700122 pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
Harvey Harrison8e24eea2008-04-30 00:55:09 -0700123 __func__, count, *ppos, buffer->page);
Akinobu Mita92f4c702007-05-09 02:33:32 -0700124 retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
125 buffer->count);
Joel Becker7063fbf2005-12-15 14:29:43 -0800126out:
Johannes Berg6d748922007-06-22 11:20:00 +0200127 mutex_unlock(&buffer->mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800128 return retval;
129}
130
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300131/**
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
151static ssize_t
152configfs_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);
207out:
208 mutex_unlock(&buffer->mutex);
209 return retval;
210}
211
Joel Becker7063fbf2005-12-15 14:29:43 -0800212
213/**
214 * fill_write_buffer - copy buffer from userspace.
215 * @buffer: data buffer for file.
Joel Becker3d0f89b2006-01-25 13:31:07 -0800216 * @buf: data from user.
Joel Becker7063fbf2005-12-15 14:29:43 -0800217 * @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
223static int
224fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size_t count)
225{
226 int error;
227
228 if (!buffer->page)
Joel Beckerff05d1c2007-01-23 17:00:45 -0800229 buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0);
Joel Becker7063fbf2005-12-15 14:29:43 -0800230 if (!buffer->page)
231 return -ENOMEM;
232
Joel Beckerb23cdde2007-06-22 13:07:02 -0700233 if (count >= SIMPLE_ATTR_SIZE)
234 count = SIMPLE_ATTR_SIZE - 1;
Joel Becker7063fbf2005-12-15 14:29:43 -0800235 error = copy_from_user(buffer->page,buf,count);
236 buffer->needs_read_fill = 1;
Joel Beckerff05d1c2007-01-23 17:00:45 -0800237 /* 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;
Joel Becker7063fbf2005-12-15 14:29:43 -0800240 return error ? -EFAULT : count;
241}
242
243
244/**
245 * flush_write_buffer - push buffer to config_item.
Joel Becker3d0f89b2006-01-25 13:31:07 -0800246 * @dentry: dentry to the attribute
Joel Becker7063fbf2005-12-15 14:29:43 -0800247 * @buffer: data buffer for file.
Joel Becker3d0f89b2006-01-25 13:31:07 -0800248 * @count: number of bytes
Joel Becker7063fbf2005-12-15 14:29:43 -0800249 *
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
255static int
256flush_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);
Joel Becker7063fbf2005-12-15 14:29:43 -0800260
Christoph Hellwig870823e2015-10-03 15:32:37 +0200261 return attr->store(item, buffer->page, count);
Joel Becker7063fbf2005-12-15 14:29:43 -0800262}
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
282static ssize_t
283configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
284{
285 struct configfs_buffer * buffer = file->private_data;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800286 ssize_t len;
Joel Becker7063fbf2005-12-15 14:29:43 -0800287
Johannes Berg6d748922007-06-22 11:20:00 +0200288 mutex_lock(&buffer->mutex);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800289 len = fill_write_buffer(buffer, buf, count);
290 if (len > 0)
Dan Carpenter71210642013-07-03 15:00:45 -0700291 len = flush_write_buffer(file->f_path.dentry, buffer, len);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800292 if (len > 0)
293 *ppos += len;
Johannes Berg6d748922007-06-22 11:20:00 +0200294 mutex_unlock(&buffer->mutex);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800295 return len;
Joel Becker7063fbf2005-12-15 14:29:43 -0800296}
297
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300298/**
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
311static ssize_t
312configfs_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;
362out:
363 mutex_unlock(&buffer->mutex);
364 return len;
365}
366
367static int check_perm(struct inode * inode, struct file * file, int type)
Joel Becker7063fbf2005-12-15 14:29:43 -0800368{
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -0800369 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);
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300371 struct configfs_bin_attribute *bin_attr = NULL;
Joel Becker7063fbf2005-12-15 14:29:43 -0800372 struct configfs_buffer * buffer;
373 struct configfs_item_operations * ops = NULL;
374 int error = 0;
375
376 if (!item || !attr)
377 goto Einval;
378
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300379 if (type & CONFIGFS_ITEM_BIN_ATTR)
380 bin_attr = to_bin_attr(file->f_path.dentry);
381
Joel Becker7063fbf2005-12-15 14:29:43 -0800382 /* 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) {
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300398 if (!(inode->i_mode & S_IWUGO))
Joel Becker7063fbf2005-12-15 14:29:43 -0800399 goto Eaccess;
400
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300401 if ((type & CONFIGFS_ITEM_ATTR) && !attr->store)
402 goto Eaccess;
403
404 if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->write)
405 goto Eaccess;
Joel Becker7063fbf2005-12-15 14:29:43 -0800406 }
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) {
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300413 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)
Joel Becker7063fbf2005-12-15 14:29:43 -0800420 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 */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700426 buffer = kzalloc(sizeof(struct configfs_buffer),GFP_KERNEL);
Chandra Seetharaman559c9ac2006-10-10 15:15:55 -0700427 if (!buffer) {
Joel Becker7063fbf2005-12-15 14:29:43 -0800428 error = -ENOMEM;
Chandra Seetharaman559c9ac2006-10-10 15:15:55 -0700429 goto Enomem;
430 }
Johannes Berg6d748922007-06-22 11:20:00 +0200431 mutex_init(&buffer->mutex);
Chandra Seetharaman559c9ac2006-10-10 15:15:55 -0700432 buffer->needs_read_fill = 1;
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300433 buffer->read_in_progress = 0;
434 buffer->write_in_progress = 0;
Chandra Seetharaman559c9ac2006-10-10 15:15:55 -0700435 buffer->ops = ops;
436 file->private_data = buffer;
Joel Becker7063fbf2005-12-15 14:29:43 -0800437 goto Done;
438
439 Einval:
440 error = -EINVAL;
441 goto Done;
442 Eaccess:
443 error = -EACCES;
Chandra Seetharaman559c9ac2006-10-10 15:15:55 -0700444 Enomem:
Joel Becker7063fbf2005-12-15 14:29:43 -0800445 module_put(attr->ca_owner);
446 Done:
447 if (error && item)
448 config_item_put(item);
449 return error;
450}
451
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300452static int configfs_release(struct inode *inode, struct file *filp)
Joel Becker7063fbf2005-12-15 14:29:43 -0800453{
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -0800454 struct config_item * item = to_item(filp->f_path.dentry->d_parent);
455 struct configfs_attribute * attr = to_attr(filp->f_path.dentry);
Joel Becker7063fbf2005-12-15 14:29:43 -0800456 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);
Johannes Berg6d748922007-06-22 11:20:00 +0200467 mutex_destroy(&buffer->mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800468 kfree(buffer);
469 }
470 return 0;
471}
472
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300473static int configfs_open_file(struct inode *inode, struct file *filp)
474{
475 return check_perm(inode, filp, CONFIGFS_ITEM_ATTR);
476}
477
478static int configfs_open_bin_file(struct inode *inode, struct file *filp)
479{
480 return check_perm(inode, filp, CONFIGFS_ITEM_BIN_ATTR);
481}
482
483static 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
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800514const struct file_operations configfs_file_operations = {
Joel Becker7063fbf2005-12-15 14:29:43 -0800515 .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
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300522const 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
Joel Becker7063fbf2005-12-15 14:29:43 -0800530/**
531 * configfs_create_file - create an attribute file for an item.
532 * @item: item we're creating for.
533 * @attr: atrribute descriptor.
534 */
535
536int configfs_create_file(struct config_item * item, const struct configfs_attribute * attr)
537{
Al Viro28444a22015-01-29 00:27:57 -0500538 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;
Joel Becker7063fbf2005-12-15 14:29:43 -0800542
Al Viro59551022016-01-22 15:40:57 -0500543 inode_lock_nested(d_inode(dir), I_MUTEX_NORMAL);
Al Viro28444a22015-01-29 00:27:57 -0500544 error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode,
545 CONFIGFS_ITEM_ATTR);
Al Viro59551022016-01-22 15:40:57 -0500546 inode_unlock(d_inode(dir));
Al Viro28444a22015-01-29 00:27:57 -0500547
548 return error;
Joel Becker7063fbf2005-12-15 14:29:43 -0800549}
550
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300551/**
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
557int 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
Al Viro59551022016-01-22 15:40:57 -0500565 inode_lock_nested(dir->d_inode, I_MUTEX_NORMAL);
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300566 error = configfs_make_dirent(parent_sd, NULL, (void *) bin_attr, mode,
567 CONFIGFS_ITEM_BIN_ATTR);
Al Viro59551022016-01-22 15:40:57 -0500568 inode_unlock(dir->d_inode);
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300569
570 return error;
571}