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1/*
2 * fs/sysfs/file.c - sysfs regular (text) file implementation
3 *
4 * Copyright (c) 2001-3 Patrick Mochel
5 * Copyright (c) 2007 SUSE Linux Products GmbH
6 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
7 *
8 * This file is released under the GPLv2.
9 *
10 * Please see Documentation/filesystems/sysfs.txt for more information.
11 */
12
13#include <linux/module.h>
14#include <linux/kobject.h>
15#include <linux/kallsyms.h>
16#include <linux/slab.h>
17#include <linux/list.h>
18#include <linux/mutex.h>
19#include <linux/seq_file.h>
20
21#include "sysfs.h"
22#include "../kernfs/kernfs-internal.h"
23
24/*
25 * Determine ktype->sysfs_ops for the given kernfs_node. This function
26 * must be called while holding an active reference.
27 */
28static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
29{
30 struct kobject *kobj = kn->parent->priv;
31
32 if (kn->flags & KERNFS_LOCKDEP)
33 lockdep_assert_held(kn);
34 return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
35}
36
37/*
38 * Reads on sysfs are handled through seq_file, which takes care of hairy
39 * details like buffering and seeking. The following function pipes
40 * sysfs_ops->show() result through seq_file.
41 */
42static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
43{
44 struct kernfs_open_file *of = sf->private;
45 struct kobject *kobj = of->kn->parent->priv;
46 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
47 ssize_t count;
48 char *buf;
49
50 /* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
51 count = seq_get_buf(sf, &buf);
52 if (count < PAGE_SIZE) {
53 seq_commit(sf, -1);
54 return 0;
55 }
56 memset(buf, 0, PAGE_SIZE);
57
58 /*
59 * Invoke show(). Control may reach here via seq file lseek even
60 * if @ops->show() isn't implemented.
61 */
62 if (ops->show) {
63 count = ops->show(kobj, of->kn->priv, buf);
64 if (count < 0)
65 return count;
66 }
67
68 /*
69 * The code works fine with PAGE_SIZE return but it's likely to
70 * indicate truncated result or overflow in normal use cases.
71 */
72 if (count >= (ssize_t)PAGE_SIZE) {
73 print_symbol("fill_read_buffer: %s returned bad count\n",
74 (unsigned long)ops->show);
75 /* Try to struggle along */
76 count = PAGE_SIZE - 1;
77 }
78 seq_commit(sf, count);
79 return 0;
80}
81
82static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
83 size_t count, loff_t pos)
84{
85 struct bin_attribute *battr = of->kn->priv;
86 struct kobject *kobj = of->kn->parent->priv;
87 loff_t size = file_inode(of->file)->i_size;
88
89 if (!count)
90 return 0;
91
92 if (size) {
93 if (pos > size)
94 return 0;
95 if (pos + count > size)
96 count = size - pos;
97 }
98
99 if (!battr->read)
100 return -EIO;
101
102 return battr->read(of->file, kobj, battr, buf, pos, count);
103}
104
105/* kernfs write callback for regular sysfs files */
106static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
107 size_t count, loff_t pos)
108{
109 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
110 struct kobject *kobj = of->kn->parent->priv;
111
112 if (!count)
113 return 0;
114
115 return ops->store(kobj, of->kn->priv, buf, count);
116}
117
118/* kernfs write callback for bin sysfs files */
119static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
120 size_t count, loff_t pos)
121{
122 struct bin_attribute *battr = of->kn->priv;
123 struct kobject *kobj = of->kn->parent->priv;
124 loff_t size = file_inode(of->file)->i_size;
125
126 if (size) {
127 if (size <= pos)
128 return 0;
129 count = min_t(ssize_t, count, size - pos);
130 }
131 if (!count)
132 return 0;
133
134 if (!battr->write)
135 return -EIO;
136
137 return battr->write(of->file, kobj, battr, buf, pos, count);
138}
139
140static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
141 struct vm_area_struct *vma)
142{
143 struct bin_attribute *battr = of->kn->priv;
144 struct kobject *kobj = of->kn->parent->priv;
145
146 return battr->mmap(of->file, kobj, battr, vma);
147}
148
149void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
150{
151 struct kernfs_node *kn = kobj->sd, *tmp;
152
153 if (kn && dir)
154 kn = kernfs_find_and_get(kn, dir);
155 else
156 kernfs_get(kn);
157
158 if (kn && attr) {
159 tmp = kernfs_find_and_get(kn, attr);
160 kernfs_put(kn);
161 kn = tmp;
162 }
163
164 if (kn) {
165 kernfs_notify(kn);
166 kernfs_put(kn);
167 }
168}
169EXPORT_SYMBOL_GPL(sysfs_notify);
170
171static const struct kernfs_ops sysfs_file_kfops_empty = {
172};
173
174static const struct kernfs_ops sysfs_file_kfops_ro = {
175 .seq_show = sysfs_kf_seq_show,
176};
177
178static const struct kernfs_ops sysfs_file_kfops_wo = {
179 .write = sysfs_kf_write,
180};
181
182static const struct kernfs_ops sysfs_file_kfops_rw = {
183 .seq_show = sysfs_kf_seq_show,
184 .write = sysfs_kf_write,
185};
186
187static const struct kernfs_ops sysfs_bin_kfops_ro = {
188 .read = sysfs_kf_bin_read,
189};
190
191static const struct kernfs_ops sysfs_bin_kfops_wo = {
192 .write = sysfs_kf_bin_write,
193};
194
195static const struct kernfs_ops sysfs_bin_kfops_rw = {
196 .read = sysfs_kf_bin_read,
197 .write = sysfs_kf_bin_write,
198};
199
200static const struct kernfs_ops sysfs_bin_kfops_mmap = {
201 .read = sysfs_kf_bin_read,
202 .write = sysfs_kf_bin_write,
203 .mmap = sysfs_kf_bin_mmap,
204};
205
206int sysfs_add_file_mode_ns(struct kernfs_node *parent,
207 const struct attribute *attr, bool is_bin,
208 umode_t mode, const void *ns)
209{
210 struct lock_class_key *key = NULL;
211 const struct kernfs_ops *ops;
212 struct kernfs_node *kn;
213 loff_t size;
214
215 if (!is_bin) {
216 struct kobject *kobj = parent->priv;
217 const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
218
219 /* every kobject with an attribute needs a ktype assigned */
220 if (WARN(!sysfs_ops, KERN_ERR
221 "missing sysfs attribute operations for kobject: %s\n",
222 kobject_name(kobj)))
223 return -EINVAL;
224
225 if (sysfs_ops->show && sysfs_ops->store)
226 ops = &sysfs_file_kfops_rw;
227 else if (sysfs_ops->show)
228 ops = &sysfs_file_kfops_ro;
229 else if (sysfs_ops->store)
230 ops = &sysfs_file_kfops_wo;
231 else
232 ops = &sysfs_file_kfops_empty;
233
234 size = PAGE_SIZE;
235 } else {
236 struct bin_attribute *battr = (void *)attr;
237
238 if (battr->mmap)
239 ops = &sysfs_bin_kfops_mmap;
240 else if (battr->read && battr->write)
241 ops = &sysfs_bin_kfops_rw;
242 else if (battr->read)
243 ops = &sysfs_bin_kfops_ro;
244 else if (battr->write)
245 ops = &sysfs_bin_kfops_wo;
246 else
247 ops = &sysfs_file_kfops_empty;
248
249 size = battr->size;
250 }
251
252#ifdef CONFIG_DEBUG_LOCK_ALLOC
253 if (!attr->ignore_lockdep)
254 key = attr->key ?: (struct lock_class_key *)&attr->skey;
255#endif
256 kn = __kernfs_create_file(parent, attr->name, mode, size, ops,
257 (void *)attr, ns, true, key);
258 if (IS_ERR(kn)) {
259 if (PTR_ERR(kn) == -EEXIST)
260 sysfs_warn_dup(parent, attr->name);
261 return PTR_ERR(kn);
262 }
263 return 0;
264}
265
266int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr,
267 bool is_bin)
268{
269 return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL);
270}
271
272/**
273 * sysfs_create_file_ns - create an attribute file for an object with custom ns
274 * @kobj: object we're creating for
275 * @attr: attribute descriptor
276 * @ns: namespace the new file should belong to
277 */
278int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
279 const void *ns)
280{
281 BUG_ON(!kobj || !kobj->sd || !attr);
282
283 return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns);
284
285}
286EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
287
288int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
289{
290 int err = 0;
291 int i;
292
293 for (i = 0; ptr[i] && !err; i++)
294 err = sysfs_create_file(kobj, ptr[i]);
295 if (err)
296 while (--i >= 0)
297 sysfs_remove_file(kobj, ptr[i]);
298 return err;
299}
300EXPORT_SYMBOL_GPL(sysfs_create_files);
301
302/**
303 * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
304 * @kobj: object we're acting for.
305 * @attr: attribute descriptor.
306 * @group: group name.
307 */
308int sysfs_add_file_to_group(struct kobject *kobj,
309 const struct attribute *attr, const char *group)
310{
311 struct kernfs_node *parent;
312 int error;
313
314 if (group) {
315 parent = kernfs_find_and_get(kobj->sd, group);
316 } else {
317 parent = kobj->sd;
318 kernfs_get(parent);
319 }
320
321 if (!parent)
322 return -ENOENT;
323
324 error = sysfs_add_file(parent, attr, false);
325 kernfs_put(parent);
326
327 return error;
328}
329EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
330
331/**
332 * sysfs_chmod_file - update the modified mode value on an object attribute.
333 * @kobj: object we're acting for.
334 * @attr: attribute descriptor.
335 * @mode: file permissions.
336 *
337 */
338int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
339 umode_t mode)
340{
341 struct kernfs_node *kn;
342 struct iattr newattrs;
343 int rc;
344
345 kn = kernfs_find_and_get(kobj->sd, attr->name);
346 if (!kn)
347 return -ENOENT;
348
349 newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
350 newattrs.ia_valid = ATTR_MODE;
351
352 rc = kernfs_setattr(kn, &newattrs);
353
354 kernfs_put(kn);
355 return rc;
356}
357EXPORT_SYMBOL_GPL(sysfs_chmod_file);
358
359/**
360 * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
361 * @kobj: object we're acting for
362 * @attr: attribute descriptor
363 * @ns: namespace tag of the file to remove
364 *
365 * Hash the attribute name and namespace tag and kill the victim.
366 */
367void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
368 const void *ns)
369{
370 struct kernfs_node *parent = kobj->sd;
371
372 kernfs_remove_by_name_ns(parent, attr->name, ns);
373}
374EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
375
376/**
377 * sysfs_remove_file_self - remove an object attribute from its own method
378 * @kobj: object we're acting for
379 * @attr: attribute descriptor
380 *
381 * See kernfs_remove_self() for details.
382 */
383bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
384{
385 struct kernfs_node *parent = kobj->sd;
386 struct kernfs_node *kn;
387 bool ret;
388
389 kn = kernfs_find_and_get(parent, attr->name);
390 if (WARN_ON_ONCE(!kn))
391 return false;
392
393 ret = kernfs_remove_self(kn);
394
395 kernfs_put(kn);
396 return ret;
397}
398
399void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
400{
401 int i;
402 for (i = 0; ptr[i]; i++)
403 sysfs_remove_file(kobj, ptr[i]);
404}
405EXPORT_SYMBOL_GPL(sysfs_remove_files);
406
407/**
408 * sysfs_remove_file_from_group - remove an attribute file from a group.
409 * @kobj: object we're acting for.
410 * @attr: attribute descriptor.
411 * @group: group name.
412 */
413void sysfs_remove_file_from_group(struct kobject *kobj,
414 const struct attribute *attr, const char *group)
415{
416 struct kernfs_node *parent;
417
418 if (group) {
419 parent = kernfs_find_and_get(kobj->sd, group);
420 } else {
421 parent = kobj->sd;
422 kernfs_get(parent);
423 }
424
425 if (parent) {
426 kernfs_remove_by_name(parent, attr->name);
427 kernfs_put(parent);
428 }
429}
430EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
431
432/**
433 * sysfs_create_bin_file - create binary file for object.
434 * @kobj: object.
435 * @attr: attribute descriptor.
436 */
437int sysfs_create_bin_file(struct kobject *kobj,
438 const struct bin_attribute *attr)
439{
440 BUG_ON(!kobj || !kobj->sd || !attr);
441
442 return sysfs_add_file(kobj->sd, &attr->attr, true);
443}
444EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
445
446/**
447 * sysfs_remove_bin_file - remove binary file for object.
448 * @kobj: object.
449 * @attr: attribute descriptor.
450 */
451void sysfs_remove_bin_file(struct kobject *kobj,
452 const struct bin_attribute *attr)
453{
454 kernfs_remove_by_name(kobj->sd, attr->attr.name);
455}
456EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/sysfs/file.c - sysfs regular (text) file implementation
4 *
5 * Copyright (c) 2001-3 Patrick Mochel
6 * Copyright (c) 2007 SUSE Linux Products GmbH
7 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
8 *
9 * Please see Documentation/filesystems/sysfs.txt for more information.
10 */
11
12#include <linux/module.h>
13#include <linux/kobject.h>
14#include <linux/slab.h>
15#include <linux/list.h>
16#include <linux/mutex.h>
17#include <linux/seq_file.h>
18
19#include "sysfs.h"
20#include "../kernfs/kernfs-internal.h"
21
22/*
23 * Determine ktype->sysfs_ops for the given kernfs_node. This function
24 * must be called while holding an active reference.
25 */
26static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
27{
28 struct kobject *kobj = kn->parent->priv;
29
30 if (kn->flags & KERNFS_LOCKDEP)
31 lockdep_assert_held(kn);
32 return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
33}
34
35/*
36 * Reads on sysfs are handled through seq_file, which takes care of hairy
37 * details like buffering and seeking. The following function pipes
38 * sysfs_ops->show() result through seq_file.
39 */
40static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
41{
42 struct kernfs_open_file *of = sf->private;
43 struct kobject *kobj = of->kn->parent->priv;
44 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
45 ssize_t count;
46 char *buf;
47
48 /* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
49 count = seq_get_buf(sf, &buf);
50 if (count < PAGE_SIZE) {
51 seq_commit(sf, -1);
52 return 0;
53 }
54 memset(buf, 0, PAGE_SIZE);
55
56 /*
57 * Invoke show(). Control may reach here via seq file lseek even
58 * if @ops->show() isn't implemented.
59 */
60 if (ops->show) {
61 count = ops->show(kobj, of->kn->priv, buf);
62 if (count < 0)
63 return count;
64 }
65
66 /*
67 * The code works fine with PAGE_SIZE return but it's likely to
68 * indicate truncated result or overflow in normal use cases.
69 */
70 if (count >= (ssize_t)PAGE_SIZE) {
71 printk("fill_read_buffer: %pS returned bad count\n",
72 ops->show);
73 /* Try to struggle along */
74 count = PAGE_SIZE - 1;
75 }
76 seq_commit(sf, count);
77 return 0;
78}
79
80static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
81 size_t count, loff_t pos)
82{
83 struct bin_attribute *battr = of->kn->priv;
84 struct kobject *kobj = of->kn->parent->priv;
85 loff_t size = file_inode(of->file)->i_size;
86
87 if (!count)
88 return 0;
89
90 if (size) {
91 if (pos >= size)
92 return 0;
93 if (pos + count > size)
94 count = size - pos;
95 }
96
97 if (!battr->read)
98 return -EIO;
99
100 return battr->read(of->file, kobj, battr, buf, pos, count);
101}
102
103/* kernfs read callback for regular sysfs files with pre-alloc */
104static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf,
105 size_t count, loff_t pos)
106{
107 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
108 struct kobject *kobj = of->kn->parent->priv;
109 ssize_t len;
110
111 /*
112 * If buf != of->prealloc_buf, we don't know how
113 * large it is, so cannot safely pass it to ->show
114 */
115 if (WARN_ON_ONCE(buf != of->prealloc_buf))
116 return 0;
117 len = ops->show(kobj, of->kn->priv, buf);
118 if (len < 0)
119 return len;
120 if (pos) {
121 if (len <= pos)
122 return 0;
123 len -= pos;
124 memmove(buf, buf + pos, len);
125 }
126 return min_t(ssize_t, count, len);
127}
128
129/* kernfs write callback for regular sysfs files */
130static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
131 size_t count, loff_t pos)
132{
133 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
134 struct kobject *kobj = of->kn->parent->priv;
135
136 if (!count)
137 return 0;
138
139 return ops->store(kobj, of->kn->priv, buf, count);
140}
141
142/* kernfs write callback for bin sysfs files */
143static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
144 size_t count, loff_t pos)
145{
146 struct bin_attribute *battr = of->kn->priv;
147 struct kobject *kobj = of->kn->parent->priv;
148 loff_t size = file_inode(of->file)->i_size;
149
150 if (size) {
151 if (size <= pos)
152 return -EFBIG;
153 count = min_t(ssize_t, count, size - pos);
154 }
155 if (!count)
156 return 0;
157
158 if (!battr->write)
159 return -EIO;
160
161 return battr->write(of->file, kobj, battr, buf, pos, count);
162}
163
164static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
165 struct vm_area_struct *vma)
166{
167 struct bin_attribute *battr = of->kn->priv;
168 struct kobject *kobj = of->kn->parent->priv;
169
170 return battr->mmap(of->file, kobj, battr, vma);
171}
172
173void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
174{
175 struct kernfs_node *kn = kobj->sd, *tmp;
176
177 if (kn && dir)
178 kn = kernfs_find_and_get(kn, dir);
179 else
180 kernfs_get(kn);
181
182 if (kn && attr) {
183 tmp = kernfs_find_and_get(kn, attr);
184 kernfs_put(kn);
185 kn = tmp;
186 }
187
188 if (kn) {
189 kernfs_notify(kn);
190 kernfs_put(kn);
191 }
192}
193EXPORT_SYMBOL_GPL(sysfs_notify);
194
195static const struct kernfs_ops sysfs_file_kfops_empty = {
196};
197
198static const struct kernfs_ops sysfs_file_kfops_ro = {
199 .seq_show = sysfs_kf_seq_show,
200};
201
202static const struct kernfs_ops sysfs_file_kfops_wo = {
203 .write = sysfs_kf_write,
204};
205
206static const struct kernfs_ops sysfs_file_kfops_rw = {
207 .seq_show = sysfs_kf_seq_show,
208 .write = sysfs_kf_write,
209};
210
211static const struct kernfs_ops sysfs_prealloc_kfops_ro = {
212 .read = sysfs_kf_read,
213 .prealloc = true,
214};
215
216static const struct kernfs_ops sysfs_prealloc_kfops_wo = {
217 .write = sysfs_kf_write,
218 .prealloc = true,
219};
220
221static const struct kernfs_ops sysfs_prealloc_kfops_rw = {
222 .read = sysfs_kf_read,
223 .write = sysfs_kf_write,
224 .prealloc = true,
225};
226
227static const struct kernfs_ops sysfs_bin_kfops_ro = {
228 .read = sysfs_kf_bin_read,
229};
230
231static const struct kernfs_ops sysfs_bin_kfops_wo = {
232 .write = sysfs_kf_bin_write,
233};
234
235static const struct kernfs_ops sysfs_bin_kfops_rw = {
236 .read = sysfs_kf_bin_read,
237 .write = sysfs_kf_bin_write,
238};
239
240static const struct kernfs_ops sysfs_bin_kfops_mmap = {
241 .read = sysfs_kf_bin_read,
242 .write = sysfs_kf_bin_write,
243 .mmap = sysfs_kf_bin_mmap,
244};
245
246int sysfs_add_file_mode_ns(struct kernfs_node *parent,
247 const struct attribute *attr, bool is_bin,
248 umode_t mode, const void *ns)
249{
250 struct lock_class_key *key = NULL;
251 const struct kernfs_ops *ops;
252 struct kernfs_node *kn;
253 loff_t size;
254
255 if (!is_bin) {
256 struct kobject *kobj = parent->priv;
257 const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
258
259 /* every kobject with an attribute needs a ktype assigned */
260 if (WARN(!sysfs_ops, KERN_ERR
261 "missing sysfs attribute operations for kobject: %s\n",
262 kobject_name(kobj)))
263 return -EINVAL;
264
265 if (sysfs_ops->show && sysfs_ops->store) {
266 if (mode & SYSFS_PREALLOC)
267 ops = &sysfs_prealloc_kfops_rw;
268 else
269 ops = &sysfs_file_kfops_rw;
270 } else if (sysfs_ops->show) {
271 if (mode & SYSFS_PREALLOC)
272 ops = &sysfs_prealloc_kfops_ro;
273 else
274 ops = &sysfs_file_kfops_ro;
275 } else if (sysfs_ops->store) {
276 if (mode & SYSFS_PREALLOC)
277 ops = &sysfs_prealloc_kfops_wo;
278 else
279 ops = &sysfs_file_kfops_wo;
280 } else
281 ops = &sysfs_file_kfops_empty;
282
283 size = PAGE_SIZE;
284 } else {
285 struct bin_attribute *battr = (void *)attr;
286
287 if (battr->mmap)
288 ops = &sysfs_bin_kfops_mmap;
289 else if (battr->read && battr->write)
290 ops = &sysfs_bin_kfops_rw;
291 else if (battr->read)
292 ops = &sysfs_bin_kfops_ro;
293 else if (battr->write)
294 ops = &sysfs_bin_kfops_wo;
295 else
296 ops = &sysfs_file_kfops_empty;
297
298 size = battr->size;
299 }
300
301#ifdef CONFIG_DEBUG_LOCK_ALLOC
302 if (!attr->ignore_lockdep)
303 key = attr->key ?: (struct lock_class_key *)&attr->skey;
304#endif
305 kn = __kernfs_create_file(parent, attr->name, mode & 0777, size, ops,
306 (void *)attr, ns, key);
307 if (IS_ERR(kn)) {
308 if (PTR_ERR(kn) == -EEXIST)
309 sysfs_warn_dup(parent, attr->name);
310 return PTR_ERR(kn);
311 }
312 return 0;
313}
314
315int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr,
316 bool is_bin)
317{
318 return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL);
319}
320
321/**
322 * sysfs_create_file_ns - create an attribute file for an object with custom ns
323 * @kobj: object we're creating for
324 * @attr: attribute descriptor
325 * @ns: namespace the new file should belong to
326 */
327int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
328 const void *ns)
329{
330 BUG_ON(!kobj || !kobj->sd || !attr);
331
332 return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns);
333
334}
335EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
336
337int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
338{
339 int err = 0;
340 int i;
341
342 for (i = 0; ptr[i] && !err; i++)
343 err = sysfs_create_file(kobj, ptr[i]);
344 if (err)
345 while (--i >= 0)
346 sysfs_remove_file(kobj, ptr[i]);
347 return err;
348}
349EXPORT_SYMBOL_GPL(sysfs_create_files);
350
351/**
352 * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
353 * @kobj: object we're acting for.
354 * @attr: attribute descriptor.
355 * @group: group name.
356 */
357int sysfs_add_file_to_group(struct kobject *kobj,
358 const struct attribute *attr, const char *group)
359{
360 struct kernfs_node *parent;
361 int error;
362
363 if (group) {
364 parent = kernfs_find_and_get(kobj->sd, group);
365 } else {
366 parent = kobj->sd;
367 kernfs_get(parent);
368 }
369
370 if (!parent)
371 return -ENOENT;
372
373 error = sysfs_add_file(parent, attr, false);
374 kernfs_put(parent);
375
376 return error;
377}
378EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
379
380/**
381 * sysfs_chmod_file - update the modified mode value on an object attribute.
382 * @kobj: object we're acting for.
383 * @attr: attribute descriptor.
384 * @mode: file permissions.
385 *
386 */
387int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
388 umode_t mode)
389{
390 struct kernfs_node *kn;
391 struct iattr newattrs;
392 int rc;
393
394 kn = kernfs_find_and_get(kobj->sd, attr->name);
395 if (!kn)
396 return -ENOENT;
397
398 newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
399 newattrs.ia_valid = ATTR_MODE;
400
401 rc = kernfs_setattr(kn, &newattrs);
402
403 kernfs_put(kn);
404 return rc;
405}
406EXPORT_SYMBOL_GPL(sysfs_chmod_file);
407
408/**
409 * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
410 * @kobj: object we're acting for
411 * @attr: attribute descriptor
412 * @ns: namespace tag of the file to remove
413 *
414 * Hash the attribute name and namespace tag and kill the victim.
415 */
416void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
417 const void *ns)
418{
419 struct kernfs_node *parent = kobj->sd;
420
421 kernfs_remove_by_name_ns(parent, attr->name, ns);
422}
423EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
424
425/**
426 * sysfs_remove_file_self - remove an object attribute from its own method
427 * @kobj: object we're acting for
428 * @attr: attribute descriptor
429 *
430 * See kernfs_remove_self() for details.
431 */
432bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
433{
434 struct kernfs_node *parent = kobj->sd;
435 struct kernfs_node *kn;
436 bool ret;
437
438 kn = kernfs_find_and_get(parent, attr->name);
439 if (WARN_ON_ONCE(!kn))
440 return false;
441
442 ret = kernfs_remove_self(kn);
443
444 kernfs_put(kn);
445 return ret;
446}
447
448void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
449{
450 int i;
451 for (i = 0; ptr[i]; i++)
452 sysfs_remove_file(kobj, ptr[i]);
453}
454EXPORT_SYMBOL_GPL(sysfs_remove_files);
455
456/**
457 * sysfs_remove_file_from_group - remove an attribute file from a group.
458 * @kobj: object we're acting for.
459 * @attr: attribute descriptor.
460 * @group: group name.
461 */
462void sysfs_remove_file_from_group(struct kobject *kobj,
463 const struct attribute *attr, const char *group)
464{
465 struct kernfs_node *parent;
466
467 if (group) {
468 parent = kernfs_find_and_get(kobj->sd, group);
469 } else {
470 parent = kobj->sd;
471 kernfs_get(parent);
472 }
473
474 if (parent) {
475 kernfs_remove_by_name(parent, attr->name);
476 kernfs_put(parent);
477 }
478}
479EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
480
481/**
482 * sysfs_create_bin_file - create binary file for object.
483 * @kobj: object.
484 * @attr: attribute descriptor.
485 */
486int sysfs_create_bin_file(struct kobject *kobj,
487 const struct bin_attribute *attr)
488{
489 BUG_ON(!kobj || !kobj->sd || !attr);
490
491 return sysfs_add_file(kobj->sd, &attr->attr, true);
492}
493EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
494
495/**
496 * sysfs_remove_bin_file - remove binary file for object.
497 * @kobj: object.
498 * @attr: attribute descriptor.
499 */
500void sysfs_remove_bin_file(struct kobject *kobj,
501 const struct bin_attribute *attr)
502{
503 kernfs_remove_by_name(kobj->sd, attr->attr.name);
504}
505EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);