2 * bin.c - binary file operations for sysfs.
7 #include <linux/errno.h>
9 #include <linux/kobject.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
13 #include <asm/uaccess.h>
18 fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
20 struct bin_attribute * attr = dentry->d_fsdata;
21 struct kobject * kobj = dentry->d_parent->d_fsdata;
23 return attr->read(kobj, buffer, off, count);
27 read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
29 char *buffer = file->private_data;
30 struct dentry *dentry = file->f_dentry;
31 int size = dentry->d_inode->i_size;
35 if (count > PAGE_SIZE)
41 if (offs + count > size)
45 ret = fill_read(dentry, buffer, offs, count);
50 if (copy_to_user(userbuf, buffer, count))
53 pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count);
61 flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
63 struct bin_attribute *attr = dentry->d_fsdata;
64 struct kobject *kobj = dentry->d_parent->d_fsdata;
66 return attr->write(kobj, buffer, offset, count);
69 static ssize_t write(struct file * file, const char __user * userbuf,
70 size_t count, loff_t * off)
72 char *buffer = file->private_data;
73 struct dentry *dentry = file->f_dentry;
74 int size = dentry->d_inode->i_size;
77 if (count > PAGE_SIZE)
82 if (offs + count > size)
86 if (copy_from_user(buffer, userbuf, count))
89 count = flush_write(dentry, buffer, offs, count);
95 static int open(struct inode * inode, struct file * file)
97 struct kobject *kobj = sysfs_get_kobject(file->f_dentry->d_parent);
98 struct bin_attribute * attr = file->f_dentry->d_fsdata;
104 /* Grab the module reference for this attribute if we have one */
106 if (!try_module_get(attr->attr.owner))
110 if ((file->f_mode & FMODE_WRITE) && !attr->write)
112 if ((file->f_mode & FMODE_READ) && !attr->read)
116 file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
117 if (!file->private_data)
124 module_put(attr->attr.owner);
131 static int release(struct inode * inode, struct file * file)
133 struct kobject * kobj = file->f_dentry->d_parent->d_fsdata;
134 struct bin_attribute * attr = file->f_dentry->d_fsdata;
135 u8 * buffer = file->private_data;
139 module_put(attr->attr.owner);
144 static struct file_operations bin_fops = {
147 .llseek = generic_file_llseek,
153 * sysfs_create_bin_file - create binary file for object.
155 * @attr: attribute descriptor.
159 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
161 struct dentry * dentry;
162 struct dentry * parent;
168 parent = kobj->dentry;
170 down(&parent->d_inode->i_sem);
171 dentry = sysfs_get_dentry(parent,attr->attr.name);
172 if (!IS_ERR(dentry)) {
173 dentry->d_fsdata = (void *)attr;
174 error = sysfs_create(dentry,
175 (attr->attr.mode & S_IALLUGO) | S_IFREG,
178 dentry->d_inode->i_size = attr->size;
179 dentry->d_inode->i_fop = &bin_fops;
183 error = PTR_ERR(dentry);
184 up(&parent->d_inode->i_sem);
190 * sysfs_remove_bin_file - remove binary file for object.
192 * @attr: attribute descriptor.
196 int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
198 sysfs_hash_and_remove(kobj->dentry,attr->attr.name);
202 EXPORT_SYMBOL(sysfs_create_bin_file);
203 EXPORT_SYMBOL(sysfs_remove_bin_file);