2 * bin.c - binary file operations for sysfs.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Matthew Wilcox
6 * Copyright (c) 2004 Silicon Graphics, Inc.
11 #include <linux/errno.h>
13 #include <linux/kernel.h>
14 #include <linux/kobject.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
18 #include <asm/uaccess.h>
19 #include <asm/semaphore.h>
29 fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
31 struct sysfs_dirent *attr_sd = dentry->d_fsdata;
32 struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
33 struct kobject * kobj = to_kobj(dentry->d_parent);
38 return attr->read(kobj, buffer, off, count);
42 read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
44 struct bin_buffer *bb = file->private_data;
45 struct dentry *dentry = file->f_path.dentry;
46 int size = dentry->d_inode->i_size;
48 int count = min_t(size_t, bytes, PAGE_SIZE);
53 if (offs + count > size)
57 mutex_lock(&bb->mutex);
59 count = fill_read(dentry, bb->buffer, offs, count);
63 if (copy_to_user(userbuf, bb->buffer, count)) {
68 pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
73 mutex_unlock(&bb->mutex);
78 flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
80 struct sysfs_dirent *attr_sd = dentry->d_fsdata;
81 struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
82 struct kobject *kobj = to_kobj(dentry->d_parent);
87 return attr->write(kobj, buffer, offset, count);
90 static ssize_t write(struct file *file, const char __user *userbuf,
91 size_t bytes, loff_t *off)
93 struct bin_buffer *bb = file->private_data;
94 struct dentry *dentry = file->f_path.dentry;
95 int size = dentry->d_inode->i_size;
97 int count = min_t(size_t, bytes, PAGE_SIZE);
102 if (offs + count > size)
106 mutex_lock(&bb->mutex);
108 if (copy_from_user(bb->buffer, userbuf, count)) {
113 count = flush_write(dentry, bb->buffer, offs, count);
118 mutex_unlock(&bb->mutex);
122 static int mmap(struct file *file, struct vm_area_struct *vma)
124 struct bin_buffer *bb = file->private_data;
125 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
126 struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
127 struct kobject *kobj = to_kobj(file->f_path.dentry->d_parent);
133 mutex_lock(&bb->mutex);
134 rc = attr->mmap(kobj, attr, vma);
135 mutex_unlock(&bb->mutex);
140 static int open(struct inode * inode, struct file * file)
142 struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
143 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
144 struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
145 struct bin_buffer *bb = NULL;
151 /* Grab the module reference for this attribute if we have one */
153 if (!try_module_get(attr->attr.owner))
157 if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
159 if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
163 bb = kzalloc(sizeof(*bb), GFP_KERNEL);
167 bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
171 mutex_init(&bb->mutex);
172 file->private_data = bb;
179 module_put(attr->attr.owner);
186 static int release(struct inode * inode, struct file * file)
188 struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent);
189 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
190 struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
191 struct bin_buffer *bb = file->private_data;
194 module_put(attr->attr.owner);
200 const struct file_operations bin_fops = {
204 .llseek = generic_file_llseek,
210 * sysfs_create_bin_file - create binary file for object.
212 * @attr: attribute descriptor.
215 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
217 BUG_ON(!kobj || !kobj->dentry || !attr);
219 return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
224 * sysfs_remove_bin_file - remove binary file for object.
226 * @attr: attribute descriptor.
229 void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
231 if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {
232 printk(KERN_ERR "%s: "
233 "bad dentry or inode or no such file: \"%s\"\n",
234 __FUNCTION__, attr->attr.name);
239 EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
240 EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);