Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
6d66f5cd | 2 | * fs/sysfs/bin.c - sysfs binary file implementation |
1da177e4 LT |
3 | * |
4 | * Copyright (c) 2003 Patrick Mochel | |
5 | * Copyright (c) 2003 Matthew Wilcox | |
6 | * Copyright (c) 2004 Silicon Graphics, Inc. | |
6d66f5cd TH |
7 | * Copyright (c) 2007 SUSE Linux Products GmbH |
8 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> | |
9 | * | |
10 | * This file is released under the GPLv2. | |
11 | * | |
12 | * Please see Documentation/filesystems/sysfs.txt for more information. | |
1da177e4 LT |
13 | */ |
14 | ||
15 | #undef DEBUG | |
16 | ||
17 | #include <linux/errno.h> | |
18 | #include <linux/fs.h> | |
995982ca | 19 | #include <linux/kernel.h> |
1da177e4 LT |
20 | #include <linux/kobject.h> |
21 | #include <linux/module.h> | |
22 | #include <linux/slab.h> | |
869512ab | 23 | #include <linux/mutex.h> |
1da177e4 LT |
24 | |
25 | #include <asm/uaccess.h> | |
26 | ||
27 | #include "sysfs.h" | |
28 | ||
eb361653 TH |
29 | struct bin_buffer { |
30 | struct mutex mutex; | |
31 | void *buffer; | |
0ab66088 | 32 | int mmapped; |
eb361653 TH |
33 | }; |
34 | ||
1da177e4 LT |
35 | static int |
36 | fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) | |
37 | { | |
3e519038 | 38 | struct sysfs_dirent *attr_sd = dentry->d_fsdata; |
b1fc3d61 TH |
39 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
40 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
0ab66088 TH |
41 | int rc; |
42 | ||
43 | /* need attr_sd for attr, its parent for kobj */ | |
44 | if (!sysfs_get_active_two(attr_sd)) | |
45 | return -ENODEV; | |
1da177e4 | 46 | |
0ab66088 TH |
47 | rc = -EIO; |
48 | if (attr->read) | |
91a69029 | 49 | rc = attr->read(kobj, attr, buffer, off, count); |
1da177e4 | 50 | |
0ab66088 TH |
51 | sysfs_put_active_two(attr_sd); |
52 | ||
53 | return rc; | |
1da177e4 LT |
54 | } |
55 | ||
56 | static ssize_t | |
93e3cd82 | 57 | read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) |
1da177e4 | 58 | { |
eb361653 | 59 | struct bin_buffer *bb = file->private_data; |
f427f5d5 | 60 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 LT |
61 | int size = dentry->d_inode->i_size; |
62 | loff_t offs = *off; | |
93e3cd82 | 63 | int count = min_t(size_t, bytes, PAGE_SIZE); |
b31ca3f5 | 64 | char *temp; |
1da177e4 LT |
65 | |
66 | if (size) { | |
67 | if (offs > size) | |
68 | return 0; | |
69 | if (offs + count > size) | |
70 | count = size - offs; | |
71 | } | |
72 | ||
b31ca3f5 NP |
73 | temp = kmalloc(count, GFP_KERNEL); |
74 | if (!temp) | |
75 | return -ENOMEM; | |
76 | ||
eb361653 TH |
77 | mutex_lock(&bb->mutex); |
78 | ||
79 | count = fill_read(dentry, bb->buffer, offs, count); | |
b31ca3f5 NP |
80 | if (count < 0) { |
81 | mutex_unlock(&bb->mutex); | |
82 | goto out_free; | |
83 | } | |
1da177e4 | 84 | |
b31ca3f5 NP |
85 | memcpy(temp, bb->buffer, count); |
86 | ||
87 | mutex_unlock(&bb->mutex); | |
88 | ||
89 | if (copy_to_user(userbuf, temp, count)) { | |
eb361653 | 90 | count = -EFAULT; |
b31ca3f5 | 91 | goto out_free; |
eb361653 | 92 | } |
1da177e4 | 93 | |
93e3cd82 | 94 | pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); |
1da177e4 LT |
95 | |
96 | *off = offs + count; | |
97 | ||
b31ca3f5 NP |
98 | out_free: |
99 | kfree(temp); | |
1da177e4 LT |
100 | return count; |
101 | } | |
102 | ||
103 | static int | |
104 | flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) | |
105 | { | |
3e519038 | 106 | struct sysfs_dirent *attr_sd = dentry->d_fsdata; |
b1fc3d61 TH |
107 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
108 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
0ab66088 TH |
109 | int rc; |
110 | ||
111 | /* need attr_sd for attr, its parent for kobj */ | |
112 | if (!sysfs_get_active_two(attr_sd)) | |
113 | return -ENODEV; | |
1da177e4 | 114 | |
0ab66088 TH |
115 | rc = -EIO; |
116 | if (attr->write) | |
91a69029 | 117 | rc = attr->write(kobj, attr, buffer, offset, count); |
1da177e4 | 118 | |
0ab66088 TH |
119 | sysfs_put_active_two(attr_sd); |
120 | ||
121 | return rc; | |
1da177e4 LT |
122 | } |
123 | ||
93e3cd82 TH |
124 | static ssize_t write(struct file *file, const char __user *userbuf, |
125 | size_t bytes, loff_t *off) | |
1da177e4 | 126 | { |
eb361653 | 127 | struct bin_buffer *bb = file->private_data; |
f427f5d5 | 128 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 LT |
129 | int size = dentry->d_inode->i_size; |
130 | loff_t offs = *off; | |
93e3cd82 | 131 | int count = min_t(size_t, bytes, PAGE_SIZE); |
b31ca3f5 | 132 | char *temp; |
1da177e4 | 133 | |
1da177e4 LT |
134 | if (size) { |
135 | if (offs > size) | |
136 | return 0; | |
137 | if (offs + count > size) | |
138 | count = size - offs; | |
139 | } | |
140 | ||
b31ca3f5 NP |
141 | temp = kmalloc(count, GFP_KERNEL); |
142 | if (!temp) | |
143 | return -ENOMEM; | |
eb361653 | 144 | |
b31ca3f5 | 145 | if (copy_from_user(temp, userbuf, count)) { |
eb361653 | 146 | count = -EFAULT; |
b31ca3f5 | 147 | goto out_free; |
eb361653 | 148 | } |
1da177e4 | 149 | |
b31ca3f5 NP |
150 | mutex_lock(&bb->mutex); |
151 | ||
152 | memcpy(bb->buffer, temp, count); | |
153 | ||
eb361653 | 154 | count = flush_write(dentry, bb->buffer, offs, count); |
b31ca3f5 NP |
155 | mutex_unlock(&bb->mutex); |
156 | ||
1da177e4 LT |
157 | if (count > 0) |
158 | *off = offs + count; | |
eb361653 | 159 | |
b31ca3f5 NP |
160 | out_free: |
161 | kfree(temp); | |
1da177e4 LT |
162 | return count; |
163 | } | |
164 | ||
165 | static int mmap(struct file *file, struct vm_area_struct *vma) | |
166 | { | |
eb361653 | 167 | struct bin_buffer *bb = file->private_data; |
3e519038 | 168 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 TH |
169 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
170 | struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; | |
eb361653 | 171 | int rc; |
1da177e4 | 172 | |
eb361653 | 173 | mutex_lock(&bb->mutex); |
0ab66088 TH |
174 | |
175 | /* need attr_sd for attr, its parent for kobj */ | |
176 | if (!sysfs_get_active_two(attr_sd)) | |
177 | return -ENODEV; | |
178 | ||
179 | rc = -EINVAL; | |
180 | if (attr->mmap) | |
181 | rc = attr->mmap(kobj, attr, vma); | |
182 | ||
183 | if (rc == 0 && !bb->mmapped) | |
184 | bb->mmapped = 1; | |
185 | else | |
186 | sysfs_put_active_two(attr_sd); | |
187 | ||
eb361653 TH |
188 | mutex_unlock(&bb->mutex); |
189 | ||
190 | return rc; | |
1da177e4 LT |
191 | } |
192 | ||
193 | static int open(struct inode * inode, struct file * file) | |
194 | { | |
3e519038 | 195 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
b1fc3d61 | 196 | struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; |
eb361653 | 197 | struct bin_buffer *bb = NULL; |
0ab66088 | 198 | int error; |
1da177e4 | 199 | |
078ce640 TH |
200 | /* binary file operations requires both @sd and its parent */ |
201 | if (!sysfs_get_active_two(attr_sd)) | |
0ab66088 | 202 | return -ENODEV; |
1da177e4 | 203 | |
1da177e4 LT |
204 | error = -EACCES; |
205 | if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) | |
7b595756 | 206 | goto err_out; |
1da177e4 | 207 | if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) |
7b595756 | 208 | goto err_out; |
1da177e4 LT |
209 | |
210 | error = -ENOMEM; | |
eb361653 TH |
211 | bb = kzalloc(sizeof(*bb), GFP_KERNEL); |
212 | if (!bb) | |
7b595756 | 213 | goto err_out; |
1da177e4 | 214 | |
eb361653 TH |
215 | bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
216 | if (!bb->buffer) | |
7b595756 | 217 | goto err_out; |
eb361653 TH |
218 | |
219 | mutex_init(&bb->mutex); | |
220 | file->private_data = bb; | |
221 | ||
078ce640 TH |
222 | /* open succeeded, put active references */ |
223 | sysfs_put_active_two(attr_sd); | |
0ab66088 | 224 | return 0; |
1da177e4 | 225 | |
7b595756 | 226 | err_out: |
078ce640 | 227 | sysfs_put_active_two(attr_sd); |
0ab66088 | 228 | kfree(bb); |
1da177e4 LT |
229 | return error; |
230 | } | |
231 | ||
232 | static int release(struct inode * inode, struct file * file) | |
233 | { | |
3e519038 | 234 | struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; |
eb361653 | 235 | struct bin_buffer *bb = file->private_data; |
1da177e4 | 236 | |
0ab66088 TH |
237 | if (bb->mmapped) |
238 | sysfs_put_active_two(attr_sd); | |
eb361653 TH |
239 | kfree(bb->buffer); |
240 | kfree(bb); | |
1da177e4 LT |
241 | return 0; |
242 | } | |
243 | ||
4b6f5d20 | 244 | const struct file_operations bin_fops = { |
1da177e4 LT |
245 | .read = read, |
246 | .write = write, | |
247 | .mmap = mmap, | |
248 | .llseek = generic_file_llseek, | |
249 | .open = open, | |
250 | .release = release, | |
251 | }; | |
252 | ||
253 | /** | |
254 | * sysfs_create_bin_file - create binary file for object. | |
255 | * @kobj: object. | |
256 | * @attr: attribute descriptor. | |
1da177e4 LT |
257 | */ |
258 | ||
259 | int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr) | |
260 | { | |
608e266a | 261 | BUG_ON(!kobj || !kobj->sd || !attr); |
1da177e4 | 262 | |
608e266a | 263 | return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); |
1da177e4 LT |
264 | } |
265 | ||
266 | ||
267 | /** | |
268 | * sysfs_remove_bin_file - remove binary file for object. | |
269 | * @kobj: object. | |
270 | * @attr: attribute descriptor. | |
1da177e4 LT |
271 | */ |
272 | ||
995982ca | 273 | void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr) |
1da177e4 | 274 | { |
5f1835da | 275 | sysfs_hash_and_remove(kobj->sd, attr->attr.name); |
1da177e4 LT |
276 | } |
277 | ||
278 | EXPORT_SYMBOL_GPL(sysfs_create_bin_file); | |
279 | EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); |