/* * bin.c - binary file operations for sysfs. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Matthew Wilcox * Copyright (c) 2004 Silicon Graphics, Inc. */ #undef DEBUG #include <linux/errno.h>#include <linux/fs.h>#include <linux/kernel.h>#include <linux/kobject.h>#include <linux/module.h>#include <linux/slab.h> #include <asm/uaccess.h>#include <asm/semaphore.h> #include "sysfs.h" static intfill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count){	struct bin_attribute * attr = to_bin_attr(dentry);	struct kobject * kobj = to_kobj(dentry->d_parent); 	if (!attr->read)		return -EIO; 	return attr->read(kobj, buffer, off, count);} static ssize_tread(struct file * file, char __user * userbuf, size_t count, loff_t * off){	char *buffer = file->private_data;	struct dentry *dentry = file->f_path.dentry;	int size = dentry->d_inode->i_size;	loff_t offs = *off;	int ret; 	if (count > PAGE_SIZE)		count = PAGE_SIZE; 	if (size) {		if (offs > size)			return 0;		if (offs + count > size)			count = size - offs;	} 	ret = fill_read(dentry, buffer, offs, count);	if (ret < 0) 		return ret;	count = ret; 	if (copy_to_user(userbuf, buffer, count))		return -EFAULT; 	pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count); 	*off = offs + count; 	return count;} static intflush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count){	struct bin_attribute *attr = to_bin_attr(dentry);	struct kobject *kobj = to_kobj(dentry->d_parent); 	if (!attr->write)		return -EIO; 	return attr->write(kobj, buffer, offset, count);} static ssize_t write(struct file * file, const char __user * userbuf,		     size_t count, loff_t * off){	char *buffer = file->private_data;	struct dentry *dentry = file->f_path.dentry;	int size = dentry->d_inode->i_size;	loff_t offs = *off; 	if (count > PAGE_SIZE)		count = PAGE_SIZE;	if (size) {		if (offs > size)			return 0;		if (offs + count > size)			count = size - offs;	} 	if (copy_from_user(buffer, userbuf, count))		return -EFAULT; 	count = flush_write(dentry, buffer, offs, count);	if (count > 0)		*off = offs + count;	return count;} static int mmap(struct file *file, struct vm_area_struct *vma){	struct dentry *dentry = file->f_path.dentry;	struct bin_attribute *attr = to_bin_attr(dentry);	struct kobject *kobj = to_kobj(dentry->d_parent); 	if (!attr->mmap)		return -EINVAL; 	return attr->mmap(kobj, attr, vma);} static int open(struct inode * inode, struct file * file){	struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);	int error = -EINVAL; 	if (!kobj || !attr)		goto Done; 	/* Grab the module reference for this attribute if we have one */	error = -ENODEV;	if (!try_module_get(attr->attr.owner)) 		goto Done; 	error = -EACCES;	if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))		goto Error;	if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))		goto Error; 	error = -ENOMEM;	file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);	if (!file->private_data)		goto Error; 	error = 0;    goto Done;  Error:	module_put(attr->attr.owner); Done:	if (error)		kobject_put(kobj);	return error;} static int release(struct inode * inode, struct file * file){	struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent);	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);	u8 * buffer = file->private_data; 	kobject_put(kobj);	module_put(attr->attr.owner);	kfree(buffer);	return 0;} const struct file_operations bin_fops = {	.read		= read,	.write		= write,	.mmap		= mmap,	.llseek		= generic_file_llseek,	.open		= open,	.release	= release,}; /** *	sysfs_create_bin_file - create binary file for object. *	@kobj:	object. *	@attr:	attribute descriptor. */ int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr){	BUG_ON(!kobj || !kobj->dentry || !attr); 	return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);}  /** *	sysfs_remove_bin_file - remove binary file for object. *	@kobj:	object. *	@attr:	attribute descriptor. */ void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr){	if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {		printk(KERN_ERR "%s: "			"bad dentry or inode or no such file: \"%s\"\n",			__FUNCTION__, attr->attr.name);		dump_stack();	}} EXPORT_SYMBOL_GPL(sysfs_create_bin_file);EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);