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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Tejun Heo6d66f5c2007-09-20 17:31:38 +09002 * fs/sysfs/bin.c - sysfs binary file implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Matthew Wilcox
6 * Copyright (c) 2004 Silicon Graphics, Inc.
Tejun Heo6d66f5c2007-09-20 17:31:38 +09007 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 */
14
15#undef DEBUG
16
17#include <linux/errno.h>
18#include <linux/fs.h>
Randy.Dunlap995982c2006-07-10 23:05:25 -070019#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/kobject.h>
21#include <linux/module.h>
22#include <linux/slab.h>
Dave Young869512a2007-07-26 14:53:53 +000023#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#include <asm/uaccess.h>
26
27#include "sysfs.h"
28
Tejun Heoeb361652007-06-14 03:45:16 +090029struct bin_buffer {
30 struct mutex mutex;
31 void *buffer;
Tejun Heo0ab66082007-06-14 03:45:16 +090032 int mmapped;
Tejun Heoeb361652007-06-14 03:45:16 +090033};
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035static int
36fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
37{
Tejun Heo3e519032007-06-14 03:45:15 +090038 struct sysfs_dirent *attr_sd = dentry->d_fsdata;
Tejun Heob1fc3d62007-09-20 16:05:11 +090039 struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
40 struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
Tejun Heo0ab66082007-06-14 03:45:16 +090041 int rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Tejun Heo0ab66082007-06-14 03:45:16 +090043 /* need attr_sd for attr, its parent for kobj */
44 if (!sysfs_get_active_two(attr_sd))
45 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Tejun Heo0ab66082007-06-14 03:45:16 +090047 rc = -EIO;
48 if (attr->read)
Zhang Rui91a69022007-06-09 13:57:22 +080049 rc = attr->read(kobj, attr, buffer, off, count);
Tejun Heo0ab66082007-06-14 03:45:16 +090050
51 sysfs_put_active_two(attr_sd);
52
53 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054}
55
56static ssize_t
Tejun Heo93e3cd822007-06-14 03:45:13 +090057read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
Tejun Heoeb361652007-06-14 03:45:16 +090059 struct bin_buffer *bb = file->private_data;
Josef "Jeff" Sipekf427f5d2006-12-08 02:36:36 -080060 struct dentry *dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 int size = dentry->d_inode->i_size;
62 loff_t offs = *off;
Tejun Heo93e3cd822007-06-14 03:45:13 +090063 int count = min_t(size_t, bytes, PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65 if (size) {
66 if (offs > size)
67 return 0;
68 if (offs + count > size)
69 count = size - offs;
70 }
71
Tejun Heoeb361652007-06-14 03:45:16 +090072 mutex_lock(&bb->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Tejun Heoeb361652007-06-14 03:45:16 +090074 count = fill_read(dentry, bb->buffer, offs, count);
75 if (count < 0)
76 goto out_unlock;
77
78 if (copy_to_user(userbuf, bb->buffer, count)) {
79 count = -EFAULT;
80 goto out_unlock;
81 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Tejun Heo93e3cd822007-06-14 03:45:13 +090083 pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85 *off = offs + count;
86
Tejun Heoeb361652007-06-14 03:45:16 +090087 out_unlock:
88 mutex_unlock(&bb->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 return count;
90}
91
92static int
93flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
94{
Tejun Heo3e519032007-06-14 03:45:15 +090095 struct sysfs_dirent *attr_sd = dentry->d_fsdata;
Tejun Heob1fc3d62007-09-20 16:05:11 +090096 struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
97 struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
Tejun Heo0ab66082007-06-14 03:45:16 +090098 int rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
Tejun Heo0ab66082007-06-14 03:45:16 +0900100 /* need attr_sd for attr, its parent for kobj */
101 if (!sysfs_get_active_two(attr_sd))
102 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Tejun Heo0ab66082007-06-14 03:45:16 +0900104 rc = -EIO;
105 if (attr->write)
Zhang Rui91a69022007-06-09 13:57:22 +0800106 rc = attr->write(kobj, attr, buffer, offset, count);
Tejun Heo0ab66082007-06-14 03:45:16 +0900107
108 sysfs_put_active_two(attr_sd);
109
110 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111}
112
Tejun Heo93e3cd822007-06-14 03:45:13 +0900113static ssize_t write(struct file *file, const char __user *userbuf,
114 size_t bytes, loff_t *off)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115{
Tejun Heoeb361652007-06-14 03:45:16 +0900116 struct bin_buffer *bb = file->private_data;
Josef "Jeff" Sipekf427f5d2006-12-08 02:36:36 -0800117 struct dentry *dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 int size = dentry->d_inode->i_size;
119 loff_t offs = *off;
Tejun Heo93e3cd822007-06-14 03:45:13 +0900120 int count = min_t(size_t, bytes, PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 if (size) {
123 if (offs > size)
124 return 0;
125 if (offs + count > size)
126 count = size - offs;
127 }
128
Tejun Heoeb361652007-06-14 03:45:16 +0900129 mutex_lock(&bb->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
Tejun Heoeb361652007-06-14 03:45:16 +0900131 if (copy_from_user(bb->buffer, userbuf, count)) {
132 count = -EFAULT;
133 goto out_unlock;
134 }
135
136 count = flush_write(dentry, bb->buffer, offs, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 if (count > 0)
138 *off = offs + count;
Tejun Heoeb361652007-06-14 03:45:16 +0900139
140 out_unlock:
141 mutex_unlock(&bb->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 return count;
143}
144
145static int mmap(struct file *file, struct vm_area_struct *vma)
146{
Tejun Heoeb361652007-06-14 03:45:16 +0900147 struct bin_buffer *bb = file->private_data;
Tejun Heo3e519032007-06-14 03:45:15 +0900148 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
Tejun Heob1fc3d62007-09-20 16:05:11 +0900149 struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
150 struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
Tejun Heoeb361652007-06-14 03:45:16 +0900151 int rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Tejun Heoeb361652007-06-14 03:45:16 +0900153 mutex_lock(&bb->mutex);
Tejun Heo0ab66082007-06-14 03:45:16 +0900154
155 /* need attr_sd for attr, its parent for kobj */
156 if (!sysfs_get_active_two(attr_sd))
157 return -ENODEV;
158
159 rc = -EINVAL;
160 if (attr->mmap)
161 rc = attr->mmap(kobj, attr, vma);
162
163 if (rc == 0 && !bb->mmapped)
164 bb->mmapped = 1;
165 else
166 sysfs_put_active_two(attr_sd);
167
Tejun Heoeb361652007-06-14 03:45:16 +0900168 mutex_unlock(&bb->mutex);
169
170 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171}
172
173static int open(struct inode * inode, struct file * file)
174{
Tejun Heo3e519032007-06-14 03:45:15 +0900175 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
Tejun Heob1fc3d62007-09-20 16:05:11 +0900176 struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
Tejun Heoeb361652007-06-14 03:45:16 +0900177 struct bin_buffer *bb = NULL;
Tejun Heo0ab66082007-06-14 03:45:16 +0900178 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
Tejun Heo078ce642007-09-20 16:05:10 +0900180 /* binary file operations requires both @sd and its parent */
181 if (!sysfs_get_active_two(attr_sd))
Tejun Heo0ab66082007-06-14 03:45:16 +0900182 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 error = -EACCES;
185 if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
Tejun Heo7b595752007-06-14 03:45:17 +0900186 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
Tejun Heo7b595752007-06-14 03:45:17 +0900188 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190 error = -ENOMEM;
Tejun Heoeb361652007-06-14 03:45:16 +0900191 bb = kzalloc(sizeof(*bb), GFP_KERNEL);
192 if (!bb)
Tejun Heo7b595752007-06-14 03:45:17 +0900193 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Tejun Heoeb361652007-06-14 03:45:16 +0900195 bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
196 if (!bb->buffer)
Tejun Heo7b595752007-06-14 03:45:17 +0900197 goto err_out;
Tejun Heoeb361652007-06-14 03:45:16 +0900198
199 mutex_init(&bb->mutex);
200 file->private_data = bb;
201
Tejun Heo078ce642007-09-20 16:05:10 +0900202 /* open succeeded, put active references */
203 sysfs_put_active_two(attr_sd);
Tejun Heo0ab66082007-06-14 03:45:16 +0900204 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
Tejun Heo7b595752007-06-14 03:45:17 +0900206 err_out:
Tejun Heo078ce642007-09-20 16:05:10 +0900207 sysfs_put_active_two(attr_sd);
Tejun Heo0ab66082007-06-14 03:45:16 +0900208 kfree(bb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 return error;
210}
211
212static int release(struct inode * inode, struct file * file)
213{
Tejun Heo3e519032007-06-14 03:45:15 +0900214 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
Tejun Heoeb361652007-06-14 03:45:16 +0900215 struct bin_buffer *bb = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
Tejun Heo0ab66082007-06-14 03:45:16 +0900217 if (bb->mmapped)
218 sysfs_put_active_two(attr_sd);
Tejun Heoeb361652007-06-14 03:45:16 +0900219 kfree(bb->buffer);
220 kfree(bb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 return 0;
222}
223
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800224const struct file_operations bin_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 .read = read,
226 .write = write,
227 .mmap = mmap,
228 .llseek = generic_file_llseek,
229 .open = open,
230 .release = release,
231};
232
233/**
234 * sysfs_create_bin_file - create binary file for object.
235 * @kobj: object.
236 * @attr: attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 */
238
239int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
240{
Tejun Heo608e2662007-06-14 04:27:22 +0900241 BUG_ON(!kobj || !kobj->sd || !attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
Tejun Heo608e2662007-06-14 04:27:22 +0900243 return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244}
245
246
247/**
248 * sysfs_remove_bin_file - remove binary file for object.
249 * @kobj: object.
250 * @attr: attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 */
252
Randy.Dunlap995982c2006-07-10 23:05:25 -0700253void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254{
Alan Stern5f1835d2007-08-16 16:13:06 -0400255 sysfs_hash_and_remove(kobj->sd, attr->attr.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
258EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
259EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);