[deliverable/linux.git] / fs / sysfs / bin.c

/*
 * 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 "sysfs.h"

static int
fill_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_t
read(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 int
flush_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 && kobj)
		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;

	if (kobj) 
		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);
Commit	Line	Data
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>
	19
	20	#include "sysfs.h"
	21
	22	static int
	23	fill_read(struct dentry dentry, char buffer, loff_t off, size_t count)
	24	{
	25	struct bin_attribute * attr = to_bin_attr(dentry);
	26	struct kobject * kobj = to_kobj(dentry->d_parent);
	27
	28	if (!attr->read)
c76d0abd	29	return -EIO;
1da177e4 LT	30
	31	return attr->read(kobj, buffer, off, count);
	32	}
	33
	34	static ssize_t
	35	read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
	36	{
	37	char *buffer = file->private_data;
f427f5d5	38	struct dentry *dentry = file->f_path.dentry;
1da177e4 LT	39	int size = dentry->d_inode->i_size;
	40	loff_t offs = *off;
	41	int ret;
	42
	43	if (count > PAGE_SIZE)
	44	count = PAGE_SIZE;
	45
	46	if (size) {
	47	if (offs > size)
	48	return 0;
	49	if (offs + count > size)
	50	count = size - offs;
	51	}
	52
	53	ret = fill_read(dentry, buffer, offs, count);
	54	if (ret < 0)
	55	return ret;
	56	count = ret;
	57
	58	if (copy_to_user(userbuf, buffer, count))
	59	return -EFAULT;
	60
	61	pr_debug("offs = %lld, off = %lld, count = %zd\n", offs, off, count);
	62
	63	*off = offs + count;
	64
	65	return count;
	66	}
	67
	68	static int
	69	flush_write(struct dentry dentry, char buffer, loff_t offset, size_t count)
	70	{
	71	struct bin_attribute *attr = to_bin_attr(dentry);
	72	struct kobject *kobj = to_kobj(dentry->d_parent);
	73
	74	if (!attr->write)
c76d0abd	75	return -EIO;
1da177e4 LT	76
	77	return attr->write(kobj, buffer, offset, count);
	78	}
	79
	80	static ssize_t write(struct file * file, const char __user * userbuf,
	81	size_t count, loff_t * off)
	82	{
	83	char *buffer = file->private_data;
f427f5d5	84	struct dentry *dentry = file->f_path.dentry;
1da177e4 LT	85	int size = dentry->d_inode->i_size;
	86	loff_t offs = *off;
	87
	88	if (count > PAGE_SIZE)
	89	count = PAGE_SIZE;
	90	if (size) {
	91	if (offs > size)
	92	return 0;
	93	if (offs + count > size)
	94	count = size - offs;
	95	}
	96
	97	if (copy_from_user(buffer, userbuf, count))
	98	return -EFAULT;
	99
	100	count = flush_write(dentry, buffer, offs, count);
	101	if (count > 0)
	102	*off = offs + count;
	103	return count;
	104	}
	105
	106	static int mmap(struct file file, struct vm_area_struct vma)
	107	{
f427f5d5	108	struct dentry *dentry = file->f_path.dentry;
1da177e4 LT	109	struct bin_attribute *attr = to_bin_attr(dentry);
	110	struct kobject *kobj = to_kobj(dentry->d_parent);
	111
	112	if (!attr->mmap)
	113	return -EINVAL;
	114
	115	return attr->mmap(kobj, attr, vma);
	116	}
	117
	118	static int open(struct inode * inode, struct file * file)
	119	{
f427f5d5 JJS	120	struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
f427f5d5 JJS	121	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
1da177e4 LT	122	int error = -EINVAL;
	123
	124	if (!kobj \|\| !attr)
	125	goto Done;
	126
	127	/* Grab the module reference for this attribute if we have one */
	128	error = -ENODEV;
	129	if (!try_module_get(attr->attr.owner))
	130	goto Done;
	131
	132	error = -EACCES;
	133	if ((file->f_mode & FMODE_WRITE) && !(attr->write \|\| attr->mmap))
	134	goto Error;
	135	if ((file->f_mode & FMODE_READ) && !(attr->read \|\| attr->mmap))
	136	goto Error;
	137
	138	error = -ENOMEM;
	139	file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
	140	if (!file->private_data)
	141	goto Error;
	142
	143	error = 0;
	144	goto Done;
	145
	146	Error:
	147	module_put(attr->attr.owner);
	148	Done:
	149	if (error && kobj)
	150	kobject_put(kobj);
	151	return error;
	152	}
	153
	154	static int release(struct inode * inode, struct file * file)
	155	{
f427f5d5 JJS	156	struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent);
f427f5d5 JJS	157	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
1da177e4 LT	158	u8 * buffer = file->private_data;
	159
	160	if (kobj)
	161	kobject_put(kobj);
	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	*/
1da177e4 LT	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);