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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * bin.c - binary file operations for sysfs. | |
3 | * | |
4 | * Copyright (c) 2003 Patrick Mochel | |
5 | * Copyright (c) 2003 Matthew Wilcox | |
6 | * Copyright (c) 2004 Silicon Graphics, Inc. | |
7 | */ | |
8 | ||
9 | #undef DEBUG | |
10 | ||
11 | #include <linux/errno.h> | |
12 | #include <linux/fs.h> | |
995982ca | 13 | #include <linux/kernel.h> |
1da177e4 LT |
14 | #include <linux/kobject.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/slab.h> | |
17 | ||
18 | #include <asm/uaccess.h> | |
94bebf4d | 19 | #include <asm/semaphore.h> |
1da177e4 LT |
20 | |
21 | #include "sysfs.h" | |
22 | ||
23 | static int | |
24 | fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count) | |
25 | { | |
26 | struct bin_attribute * attr = to_bin_attr(dentry); | |
27 | struct kobject * kobj = to_kobj(dentry->d_parent); | |
28 | ||
29 | if (!attr->read) | |
c76d0abd | 30 | return -EIO; |
1da177e4 LT |
31 | |
32 | return attr->read(kobj, buffer, off, count); | |
33 | } | |
34 | ||
35 | static ssize_t | |
36 | read(struct file * file, char __user * userbuf, size_t count, loff_t * off) | |
37 | { | |
38 | char *buffer = file->private_data; | |
f427f5d5 | 39 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 LT |
40 | int size = dentry->d_inode->i_size; |
41 | loff_t offs = *off; | |
42 | int ret; | |
43 | ||
44 | if (count > PAGE_SIZE) | |
45 | count = PAGE_SIZE; | |
46 | ||
47 | if (size) { | |
48 | if (offs > size) | |
49 | return 0; | |
50 | if (offs + count > size) | |
51 | count = size - offs; | |
52 | } | |
53 | ||
54 | ret = fill_read(dentry, buffer, offs, count); | |
55 | if (ret < 0) | |
56 | return ret; | |
57 | count = ret; | |
58 | ||
59 | if (copy_to_user(userbuf, buffer, count)) | |
60 | return -EFAULT; | |
61 | ||
62 | pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count); | |
63 | ||
64 | *off = offs + count; | |
65 | ||
66 | return count; | |
67 | } | |
68 | ||
69 | static int | |
70 | flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count) | |
71 | { | |
72 | struct bin_attribute *attr = to_bin_attr(dentry); | |
73 | struct kobject *kobj = to_kobj(dentry->d_parent); | |
74 | ||
75 | if (!attr->write) | |
c76d0abd | 76 | return -EIO; |
1da177e4 LT |
77 | |
78 | return attr->write(kobj, buffer, offset, count); | |
79 | } | |
80 | ||
81 | static ssize_t write(struct file * file, const char __user * userbuf, | |
82 | size_t count, loff_t * off) | |
83 | { | |
84 | char *buffer = file->private_data; | |
f427f5d5 | 85 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 LT |
86 | int size = dentry->d_inode->i_size; |
87 | loff_t offs = *off; | |
88 | ||
89 | if (count > PAGE_SIZE) | |
90 | count = PAGE_SIZE; | |
91 | if (size) { | |
92 | if (offs > size) | |
93 | return 0; | |
94 | if (offs + count > size) | |
95 | count = size - offs; | |
96 | } | |
97 | ||
98 | if (copy_from_user(buffer, userbuf, count)) | |
99 | return -EFAULT; | |
100 | ||
101 | count = flush_write(dentry, buffer, offs, count); | |
102 | if (count > 0) | |
103 | *off = offs + count; | |
104 | return count; | |
105 | } | |
106 | ||
107 | static int mmap(struct file *file, struct vm_area_struct *vma) | |
108 | { | |
f427f5d5 | 109 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 LT |
110 | struct bin_attribute *attr = to_bin_attr(dentry); |
111 | struct kobject *kobj = to_kobj(dentry->d_parent); | |
112 | ||
113 | if (!attr->mmap) | |
114 | return -EINVAL; | |
115 | ||
116 | return attr->mmap(kobj, attr, vma); | |
117 | } | |
118 | ||
119 | static int open(struct inode * inode, struct file * file) | |
120 | { | |
f427f5d5 JJS |
121 | struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent); |
122 | struct bin_attribute * attr = to_bin_attr(file->f_path.dentry); | |
1da177e4 LT |
123 | int error = -EINVAL; |
124 | ||
125 | if (!kobj || !attr) | |
126 | goto Done; | |
127 | ||
128 | /* Grab the module reference for this attribute if we have one */ | |
129 | error = -ENODEV; | |
130 | if (!try_module_get(attr->attr.owner)) | |
131 | goto Done; | |
132 | ||
133 | error = -EACCES; | |
134 | if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) | |
135 | goto Error; | |
136 | if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) | |
137 | goto Error; | |
138 | ||
139 | error = -ENOMEM; | |
140 | file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
141 | if (!file->private_data) | |
142 | goto Error; | |
143 | ||
144 | error = 0; | |
145 | goto Done; | |
146 | ||
147 | Error: | |
148 | module_put(attr->attr.owner); | |
149 | Done: | |
f7506536 | 150 | if (error) |
1da177e4 LT |
151 | kobject_put(kobj); |
152 | return error; | |
153 | } | |
154 | ||
155 | static int release(struct inode * inode, struct file * file) | |
156 | { | |
f427f5d5 JJS |
157 | struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent); |
158 | struct bin_attribute * attr = to_bin_attr(file->f_path.dentry); | |
1da177e4 LT |
159 | u8 * buffer = file->private_data; |
160 | ||
f7506536 | 161 | kobject_put(kobj); |
1da177e4 LT |
162 | module_put(attr->attr.owner); |
163 | kfree(buffer); | |
164 | return 0; | |
165 | } | |
166 | ||
4b6f5d20 | 167 | const struct file_operations bin_fops = { |
1da177e4 LT |
168 | .read = read, |
169 | .write = write, | |
170 | .mmap = mmap, | |
171 | .llseek = generic_file_llseek, | |
172 | .open = open, | |
173 | .release = release, | |
174 | }; | |
175 | ||
176 | /** | |
177 | * sysfs_create_bin_file - create binary file for object. | |
178 | * @kobj: object. | |
179 | * @attr: attribute descriptor. | |
1da177e4 LT |
180 | */ |
181 | ||
182 | int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr) | |
183 | { | |
184 | BUG_ON(!kobj || !kobj->dentry || !attr); | |
185 | ||
186 | return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR); | |
187 | } | |
188 | ||
189 | ||
190 | /** | |
191 | * sysfs_remove_bin_file - remove binary file for object. | |
192 | * @kobj: object. | |
193 | * @attr: attribute descriptor. | |
1da177e4 LT |
194 | */ |
195 | ||
995982ca | 196 | void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr) |
1da177e4 | 197 | { |
995982ca RD |
198 | if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) { |
199 | printk(KERN_ERR "%s: " | |
200 | "bad dentry or inode or no such file: \"%s\"\n", | |
201 | __FUNCTION__, attr->attr.name); | |
202 | dump_stack(); | |
203 | } | |
1da177e4 LT |
204 | } |
205 | ||
206 | EXPORT_SYMBOL_GPL(sysfs_create_bin_file); | |
207 | EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); |