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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 read callback for regular sysfs files with pre-alloc */
106static ssize_t sysfs_kf_read(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 ssize_t len;
112
113 /*
114 * If buf != of->prealloc_buf, we don't know how
115 * large it is, so cannot safely pass it to ->show
116 */
117 if (WARN_ON_ONCE(buf != of->prealloc_buf))
118 return 0;
119 len = ops->show(kobj, of->kn->priv, buf);
120 if (len < 0)
121 return len;
122 if (pos) {
123 if (len <= pos)
124 return 0;
125 len -= pos;
126 memmove(buf, buf + pos, len);
127 }
128 return min_t(ssize_t, count, len);
129}
130
131/* kernfs write callback for regular sysfs files */
132static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
133 size_t count, loff_t pos)
134{
135 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
136 struct kobject *kobj = of->kn->parent->priv;
137
138 if (!count)
139 return 0;
140
141 return ops->store(kobj, of->kn->priv, buf, count);
142}
143
144/* kernfs write callback for bin sysfs files */
145static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
146 size_t count, loff_t pos)
147{
148 struct bin_attribute *battr = of->kn->priv;
149 struct kobject *kobj = of->kn->parent->priv;
150 loff_t size = file_inode(of->file)->i_size;
151
152 if (size) {
153 if (size <= pos)
154 return -EFBIG;
155 count = min_t(ssize_t, count, size - pos);
156 }
157 if (!count)
158 return 0;
159
160 if (!battr->write)
161 return -EIO;
162
163 return battr->write(of->file, kobj, battr, buf, pos, count);
164}
165
166static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
167 struct vm_area_struct *vma)
168{
169 struct bin_attribute *battr = of->kn->priv;
170 struct kobject *kobj = of->kn->parent->priv;
171
172 return battr->mmap(of->file, kobj, battr, vma);
173}
174
175void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
176{
177 struct kernfs_node *kn = kobj->sd, *tmp;
178
179 if (kn && dir)
180 kn = kernfs_find_and_get(kn, dir);
181 else
182 kernfs_get(kn);
183
184 if (kn && attr) {
185 tmp = kernfs_find_and_get(kn, attr);
186 kernfs_put(kn);
187 kn = tmp;
188 }
189
190 if (kn) {
191 kernfs_notify(kn);
192 kernfs_put(kn);
193 }
194}
195EXPORT_SYMBOL_GPL(sysfs_notify);
196
197static const struct kernfs_ops sysfs_file_kfops_empty = {
198};
199
200static const struct kernfs_ops sysfs_file_kfops_ro = {
201 .seq_show = sysfs_kf_seq_show,
202};
203
204static const struct kernfs_ops sysfs_file_kfops_wo = {
205 .write = sysfs_kf_write,
206};
207
208static const struct kernfs_ops sysfs_file_kfops_rw = {
209 .seq_show = sysfs_kf_seq_show,
210 .write = sysfs_kf_write,
211};
212
213static const struct kernfs_ops sysfs_prealloc_kfops_ro = {
214 .read = sysfs_kf_read,
215 .prealloc = true,
216};
217
218static const struct kernfs_ops sysfs_prealloc_kfops_wo = {
219 .write = sysfs_kf_write,
220 .prealloc = true,
221};
222
223static const struct kernfs_ops sysfs_prealloc_kfops_rw = {
224 .read = sysfs_kf_read,
225 .write = sysfs_kf_write,
226 .prealloc = true,
227};
228
229static const struct kernfs_ops sysfs_bin_kfops_ro = {
230 .read = sysfs_kf_bin_read,
231};
232
233static const struct kernfs_ops sysfs_bin_kfops_wo = {
234 .write = sysfs_kf_bin_write,
235};
236
237static const struct kernfs_ops sysfs_bin_kfops_rw = {
238 .read = sysfs_kf_bin_read,
239 .write = sysfs_kf_bin_write,
240};
241
242static const struct kernfs_ops sysfs_bin_kfops_mmap = {
243 .read = sysfs_kf_bin_read,
244 .write = sysfs_kf_bin_write,
245 .mmap = sysfs_kf_bin_mmap,
246};
247
248int sysfs_add_file_mode_ns(struct kernfs_node *parent,
249 const struct attribute *attr, bool is_bin,
250 umode_t mode, const void *ns)
251{
252 struct lock_class_key *key = NULL;
253 const struct kernfs_ops *ops;
254 struct kernfs_node *kn;
255 loff_t size;
256
257 if (!is_bin) {
258 struct kobject *kobj = parent->priv;
259 const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
260
261 /* every kobject with an attribute needs a ktype assigned */
262 if (WARN(!sysfs_ops, KERN_ERR
263 "missing sysfs attribute operations for kobject: %s\n",
264 kobject_name(kobj)))
265 return -EINVAL;
266
267 if (sysfs_ops->show && sysfs_ops->store) {
268 if (mode & SYSFS_PREALLOC)
269 ops = &sysfs_prealloc_kfops_rw;
270 else
271 ops = &sysfs_file_kfops_rw;
272 } else if (sysfs_ops->show) {
273 if (mode & SYSFS_PREALLOC)
274 ops = &sysfs_prealloc_kfops_ro;
275 else
276 ops = &sysfs_file_kfops_ro;
277 } else if (sysfs_ops->store) {
278 if (mode & SYSFS_PREALLOC)
279 ops = &sysfs_prealloc_kfops_wo;
280 else
281 ops = &sysfs_file_kfops_wo;
282 } else
283 ops = &sysfs_file_kfops_empty;
284
285 size = PAGE_SIZE;
286 } else {
287 struct bin_attribute *battr = (void *)attr;
288
289 if (battr->mmap)
290 ops = &sysfs_bin_kfops_mmap;
291 else if (battr->read && battr->write)
292 ops = &sysfs_bin_kfops_rw;
293 else if (battr->read)
294 ops = &sysfs_bin_kfops_ro;
295 else if (battr->write)
296 ops = &sysfs_bin_kfops_wo;
297 else
298 ops = &sysfs_file_kfops_empty;
299
300 size = battr->size;
301 }
302
303#ifdef CONFIG_DEBUG_LOCK_ALLOC
304 if (!attr->ignore_lockdep)
305 key = attr->key ?: (struct lock_class_key *)&attr->skey;
306#endif
307 kn = __kernfs_create_file(parent, attr->name, mode & 0777, size, ops,
308 (void *)attr, ns, key);
309 if (IS_ERR(kn)) {
310 if (PTR_ERR(kn) == -EEXIST)
311 sysfs_warn_dup(parent, attr->name);
312 return PTR_ERR(kn);
313 }
314 return 0;
315}
316
317int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr,
318 bool is_bin)
319{
320 return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL);
321}
322
323/**
324 * sysfs_create_file_ns - create an attribute file for an object with custom ns
325 * @kobj: object we're creating for
326 * @attr: attribute descriptor
327 * @ns: namespace the new file should belong to
328 */
329int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
330 const void *ns)
331{
332 BUG_ON(!kobj || !kobj->sd || !attr);
333
334 return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns);
335
336}
337EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
338
339int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
340{
341 int err = 0;
342 int i;
343
344 for (i = 0; ptr[i] && !err; i++)
345 err = sysfs_create_file(kobj, ptr[i]);
346 if (err)
347 while (--i >= 0)
348 sysfs_remove_file(kobj, ptr[i]);
349 return err;
350}
351EXPORT_SYMBOL_GPL(sysfs_create_files);
352
353/**
354 * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
355 * @kobj: object we're acting for.
356 * @attr: attribute descriptor.
357 * @group: group name.
358 */
359int sysfs_add_file_to_group(struct kobject *kobj,
360 const struct attribute *attr, const char *group)
361{
362 struct kernfs_node *parent;
363 int error;
364
365 if (group) {
366 parent = kernfs_find_and_get(kobj->sd, group);
367 } else {
368 parent = kobj->sd;
369 kernfs_get(parent);
370 }
371
372 if (!parent)
373 return -ENOENT;
374
375 error = sysfs_add_file(parent, attr, false);
376 kernfs_put(parent);
377
378 return error;
379}
380EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
381
382/**
383 * sysfs_chmod_file - update the modified mode value on an object attribute.
384 * @kobj: object we're acting for.
385 * @attr: attribute descriptor.
386 * @mode: file permissions.
387 *
388 */
389int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
390 umode_t mode)
391{
392 struct kernfs_node *kn;
393 struct iattr newattrs;
394 int rc;
395
396 kn = kernfs_find_and_get(kobj->sd, attr->name);
397 if (!kn)
398 return -ENOENT;
399
400 newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
401 newattrs.ia_valid = ATTR_MODE;
402
403 rc = kernfs_setattr(kn, &newattrs);
404
405 kernfs_put(kn);
406 return rc;
407}
408EXPORT_SYMBOL_GPL(sysfs_chmod_file);
409
410/**
411 * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
412 * @kobj: object we're acting for
413 * @attr: attribute descriptor
414 * @ns: namespace tag of the file to remove
415 *
416 * Hash the attribute name and namespace tag and kill the victim.
417 */
418void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
419 const void *ns)
420{
421 struct kernfs_node *parent = kobj->sd;
422
423 kernfs_remove_by_name_ns(parent, attr->name, ns);
424}
425EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
426
427/**
428 * sysfs_remove_file_self - remove an object attribute from its own method
429 * @kobj: object we're acting for
430 * @attr: attribute descriptor
431 *
432 * See kernfs_remove_self() for details.
433 */
434bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
435{
436 struct kernfs_node *parent = kobj->sd;
437 struct kernfs_node *kn;
438 bool ret;
439
440 kn = kernfs_find_and_get(parent, attr->name);
441 if (WARN_ON_ONCE(!kn))
442 return false;
443
444 ret = kernfs_remove_self(kn);
445
446 kernfs_put(kn);
447 return ret;
448}
449
450void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
451{
452 int i;
453 for (i = 0; ptr[i]; i++)
454 sysfs_remove_file(kobj, ptr[i]);
455}
456EXPORT_SYMBOL_GPL(sysfs_remove_files);
457
458/**
459 * sysfs_remove_file_from_group - remove an attribute file from a group.
460 * @kobj: object we're acting for.
461 * @attr: attribute descriptor.
462 * @group: group name.
463 */
464void sysfs_remove_file_from_group(struct kobject *kobj,
465 const struct attribute *attr, const char *group)
466{
467 struct kernfs_node *parent;
468
469 if (group) {
470 parent = kernfs_find_and_get(kobj->sd, group);
471 } else {
472 parent = kobj->sd;
473 kernfs_get(parent);
474 }
475
476 if (parent) {
477 kernfs_remove_by_name(parent, attr->name);
478 kernfs_put(parent);
479 }
480}
481EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
482
483/**
484 * sysfs_create_bin_file - create binary file for object.
485 * @kobj: object.
486 * @attr: attribute descriptor.
487 */
488int sysfs_create_bin_file(struct kobject *kobj,
489 const struct bin_attribute *attr)
490{
491 BUG_ON(!kobj || !kobj->sd || !attr);
492
493 return sysfs_add_file(kobj->sd, &attr->attr, true);
494}
495EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
496
497/**
498 * sysfs_remove_bin_file - remove binary file for object.
499 * @kobj: object.
500 * @attr: attribute descriptor.
501 */
502void sysfs_remove_bin_file(struct kobject *kobj,
503 const struct bin_attribute *attr)
504{
505 kernfs_remove_by_name(kobj->sd, attr->attr.name);
506}
507EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
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 read callback for regular sysfs files with pre-alloc */
106static ssize_t sysfs_kf_read(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 size_t len;
112
113 /*
114 * If buf != of->prealloc_buf, we don't know how
115 * large it is, so cannot safely pass it to ->show
116 */
117 if (pos || WARN_ON_ONCE(buf != of->prealloc_buf))
118 return 0;
119 len = ops->show(kobj, of->kn->priv, buf);
120 return min(count, len);
121}
122
123/* kernfs write callback for regular sysfs files */
124static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
125 size_t count, loff_t pos)
126{
127 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
128 struct kobject *kobj = of->kn->parent->priv;
129
130 if (!count)
131 return 0;
132
133 return ops->store(kobj, of->kn->priv, buf, count);
134}
135
136/* kernfs write callback for bin sysfs files */
137static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
138 size_t count, loff_t pos)
139{
140 struct bin_attribute *battr = of->kn->priv;
141 struct kobject *kobj = of->kn->parent->priv;
142 loff_t size = file_inode(of->file)->i_size;
143
144 if (size) {
145 if (size <= pos)
146 return -EFBIG;
147 count = min_t(ssize_t, count, size - pos);
148 }
149 if (!count)
150 return 0;
151
152 if (!battr->write)
153 return -EIO;
154
155 return battr->write(of->file, kobj, battr, buf, pos, count);
156}
157
158static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
159 struct vm_area_struct *vma)
160{
161 struct bin_attribute *battr = of->kn->priv;
162 struct kobject *kobj = of->kn->parent->priv;
163
164 return battr->mmap(of->file, kobj, battr, vma);
165}
166
167void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
168{
169 struct kernfs_node *kn = kobj->sd, *tmp;
170
171 if (kn && dir)
172 kn = kernfs_find_and_get(kn, dir);
173 else
174 kernfs_get(kn);
175
176 if (kn && attr) {
177 tmp = kernfs_find_and_get(kn, attr);
178 kernfs_put(kn);
179 kn = tmp;
180 }
181
182 if (kn) {
183 kernfs_notify(kn);
184 kernfs_put(kn);
185 }
186}
187EXPORT_SYMBOL_GPL(sysfs_notify);
188
189static const struct kernfs_ops sysfs_file_kfops_empty = {
190};
191
192static const struct kernfs_ops sysfs_file_kfops_ro = {
193 .seq_show = sysfs_kf_seq_show,
194};
195
196static const struct kernfs_ops sysfs_file_kfops_wo = {
197 .write = sysfs_kf_write,
198};
199
200static const struct kernfs_ops sysfs_file_kfops_rw = {
201 .seq_show = sysfs_kf_seq_show,
202 .write = sysfs_kf_write,
203};
204
205static const struct kernfs_ops sysfs_prealloc_kfops_ro = {
206 .read = sysfs_kf_read,
207 .prealloc = true,
208};
209
210static const struct kernfs_ops sysfs_prealloc_kfops_wo = {
211 .write = sysfs_kf_write,
212 .prealloc = true,
213};
214
215static const struct kernfs_ops sysfs_prealloc_kfops_rw = {
216 .read = sysfs_kf_read,
217 .write = sysfs_kf_write,
218 .prealloc = true,
219};
220
221static const struct kernfs_ops sysfs_bin_kfops_ro = {
222 .read = sysfs_kf_bin_read,
223};
224
225static const struct kernfs_ops sysfs_bin_kfops_wo = {
226 .write = sysfs_kf_bin_write,
227};
228
229static const struct kernfs_ops sysfs_bin_kfops_rw = {
230 .read = sysfs_kf_bin_read,
231 .write = sysfs_kf_bin_write,
232};
233
234static const struct kernfs_ops sysfs_bin_kfops_mmap = {
235 .read = sysfs_kf_bin_read,
236 .write = sysfs_kf_bin_write,
237 .mmap = sysfs_kf_bin_mmap,
238};
239
240int sysfs_add_file_mode_ns(struct kernfs_node *parent,
241 const struct attribute *attr, bool is_bin,
242 umode_t mode, const void *ns)
243{
244 struct lock_class_key *key = NULL;
245 const struct kernfs_ops *ops;
246 struct kernfs_node *kn;
247 loff_t size;
248
249 if (!is_bin) {
250 struct kobject *kobj = parent->priv;
251 const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
252
253 /* every kobject with an attribute needs a ktype assigned */
254 if (WARN(!sysfs_ops, KERN_ERR
255 "missing sysfs attribute operations for kobject: %s\n",
256 kobject_name(kobj)))
257 return -EINVAL;
258
259 if (sysfs_ops->show && sysfs_ops->store) {
260 if (mode & SYSFS_PREALLOC)
261 ops = &sysfs_prealloc_kfops_rw;
262 else
263 ops = &sysfs_file_kfops_rw;
264 } else if (sysfs_ops->show) {
265 if (mode & SYSFS_PREALLOC)
266 ops = &sysfs_prealloc_kfops_ro;
267 else
268 ops = &sysfs_file_kfops_ro;
269 } else if (sysfs_ops->store) {
270 if (mode & SYSFS_PREALLOC)
271 ops = &sysfs_prealloc_kfops_wo;
272 else
273 ops = &sysfs_file_kfops_wo;
274 } else
275 ops = &sysfs_file_kfops_empty;
276
277 size = PAGE_SIZE;
278 } else {
279 struct bin_attribute *battr = (void *)attr;
280
281 if (battr->mmap)
282 ops = &sysfs_bin_kfops_mmap;
283 else if (battr->read && battr->write)
284 ops = &sysfs_bin_kfops_rw;
285 else if (battr->read)
286 ops = &sysfs_bin_kfops_ro;
287 else if (battr->write)
288 ops = &sysfs_bin_kfops_wo;
289 else
290 ops = &sysfs_file_kfops_empty;
291
292 size = battr->size;
293 }
294
295#ifdef CONFIG_DEBUG_LOCK_ALLOC
296 if (!attr->ignore_lockdep)
297 key = attr->key ?: (struct lock_class_key *)&attr->skey;
298#endif
299 kn = __kernfs_create_file(parent, attr->name, mode & 0777, size, ops,
300 (void *)attr, ns, key);
301 if (IS_ERR(kn)) {
302 if (PTR_ERR(kn) == -EEXIST)
303 sysfs_warn_dup(parent, attr->name);
304 return PTR_ERR(kn);
305 }
306 return 0;
307}
308
309int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr,
310 bool is_bin)
311{
312 return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL);
313}
314
315/**
316 * sysfs_create_file_ns - create an attribute file for an object with custom ns
317 * @kobj: object we're creating for
318 * @attr: attribute descriptor
319 * @ns: namespace the new file should belong to
320 */
321int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
322 const void *ns)
323{
324 BUG_ON(!kobj || !kobj->sd || !attr);
325
326 return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns);
327
328}
329EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
330
331int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
332{
333 int err = 0;
334 int i;
335
336 for (i = 0; ptr[i] && !err; i++)
337 err = sysfs_create_file(kobj, ptr[i]);
338 if (err)
339 while (--i >= 0)
340 sysfs_remove_file(kobj, ptr[i]);
341 return err;
342}
343EXPORT_SYMBOL_GPL(sysfs_create_files);
344
345/**
346 * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
347 * @kobj: object we're acting for.
348 * @attr: attribute descriptor.
349 * @group: group name.
350 */
351int sysfs_add_file_to_group(struct kobject *kobj,
352 const struct attribute *attr, const char *group)
353{
354 struct kernfs_node *parent;
355 int error;
356
357 if (group) {
358 parent = kernfs_find_and_get(kobj->sd, group);
359 } else {
360 parent = kobj->sd;
361 kernfs_get(parent);
362 }
363
364 if (!parent)
365 return -ENOENT;
366
367 error = sysfs_add_file(parent, attr, false);
368 kernfs_put(parent);
369
370 return error;
371}
372EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
373
374/**
375 * sysfs_chmod_file - update the modified mode value on an object attribute.
376 * @kobj: object we're acting for.
377 * @attr: attribute descriptor.
378 * @mode: file permissions.
379 *
380 */
381int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
382 umode_t mode)
383{
384 struct kernfs_node *kn;
385 struct iattr newattrs;
386 int rc;
387
388 kn = kernfs_find_and_get(kobj->sd, attr->name);
389 if (!kn)
390 return -ENOENT;
391
392 newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
393 newattrs.ia_valid = ATTR_MODE;
394
395 rc = kernfs_setattr(kn, &newattrs);
396
397 kernfs_put(kn);
398 return rc;
399}
400EXPORT_SYMBOL_GPL(sysfs_chmod_file);
401
402/**
403 * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
404 * @kobj: object we're acting for
405 * @attr: attribute descriptor
406 * @ns: namespace tag of the file to remove
407 *
408 * Hash the attribute name and namespace tag and kill the victim.
409 */
410void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
411 const void *ns)
412{
413 struct kernfs_node *parent = kobj->sd;
414
415 kernfs_remove_by_name_ns(parent, attr->name, ns);
416}
417EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
418
419/**
420 * sysfs_remove_file_self - remove an object attribute from its own method
421 * @kobj: object we're acting for
422 * @attr: attribute descriptor
423 *
424 * See kernfs_remove_self() for details.
425 */
426bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
427{
428 struct kernfs_node *parent = kobj->sd;
429 struct kernfs_node *kn;
430 bool ret;
431
432 kn = kernfs_find_and_get(parent, attr->name);
433 if (WARN_ON_ONCE(!kn))
434 return false;
435
436 ret = kernfs_remove_self(kn);
437
438 kernfs_put(kn);
439 return ret;
440}
441
442void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
443{
444 int i;
445 for (i = 0; ptr[i]; i++)
446 sysfs_remove_file(kobj, ptr[i]);
447}
448EXPORT_SYMBOL_GPL(sysfs_remove_files);
449
450/**
451 * sysfs_remove_file_from_group - remove an attribute file from a group.
452 * @kobj: object we're acting for.
453 * @attr: attribute descriptor.
454 * @group: group name.
455 */
456void sysfs_remove_file_from_group(struct kobject *kobj,
457 const struct attribute *attr, const char *group)
458{
459 struct kernfs_node *parent;
460
461 if (group) {
462 parent = kernfs_find_and_get(kobj->sd, group);
463 } else {
464 parent = kobj->sd;
465 kernfs_get(parent);
466 }
467
468 if (parent) {
469 kernfs_remove_by_name(parent, attr->name);
470 kernfs_put(parent);
471 }
472}
473EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
474
475/**
476 * sysfs_create_bin_file - create binary file for object.
477 * @kobj: object.
478 * @attr: attribute descriptor.
479 */
480int sysfs_create_bin_file(struct kobject *kobj,
481 const struct bin_attribute *attr)
482{
483 BUG_ON(!kobj || !kobj->sd || !attr);
484
485 return sysfs_add_file(kobj->sd, &attr->attr, true);
486}
487EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
488
489/**
490 * sysfs_remove_bin_file - remove binary file for object.
491 * @kobj: object.
492 * @attr: attribute descriptor.
493 */
494void sysfs_remove_bin_file(struct kobject *kobj,
495 const struct bin_attribute *attr)
496{
497 kernfs_remove_by_name(kobj->sd, attr->attr.name);
498}
499EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);