Esempio n. 1
0
static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
{
	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
	struct kiocb kiocb;
	struct iov_iter iter;
	ssize_t ret;

	init_sync_kiocb(&kiocb, filp);
	kiocb.ki_pos = *ppos;
	iov_iter_init(&iter, WRITE, &iov, 1, len);

	ret = filp->f_op->write_iter(&kiocb, &iter);
	BUG_ON(ret == -EIOCBQUEUED);
	if (ret > 0)
		*ppos = kiocb.ki_pos;
	return ret;
}

ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
		    loff_t *pos)
{
	if (file->f_op->write)
		return file->f_op->write(file, p, count, pos);
	else if (file->f_op->write_iter)
		return new_sync_write(file, p, count, pos);
	else
		return -EINVAL;
}
EXPORT_SYMBOL(__vfs_write);

ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
{
	mm_segment_t old_fs;
	const char __user *p;
	ssize_t ret;

	if (!(file->f_mode & FMODE_CAN_WRITE))
		return -EINVAL;

	old_fs = get_fs();
	set_fs(get_ds());
	p = (__force const char __user *)buf;
	if (count > MAX_RW_COUNT)
		count =  MAX_RW_COUNT;
	ret = __vfs_write(file, p, count, pos);
	set_fs(old_fs);
	if (ret > 0) {
		fsnotify_modify(file);
		add_wchar(current, ret);
	}
	inc_syscw(current);
	return ret;
}
Esempio n. 2
0
ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
{
	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
	struct kiocb kiocb;
	ssize_t ret;

	init_sync_kiocb(&kiocb, filp);
	kiocb.ki_pos = *ppos;

	ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
	BUG_ON(ret == -EIOCBQUEUED);
	*ppos = kiocb.ki_pos;
	return ret;
}

EXPORT_SYMBOL(do_sync_write);

ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
{
	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
	struct kiocb kiocb;
	struct iov_iter iter;
	ssize_t ret;

	init_sync_kiocb(&kiocb, filp);
	kiocb.ki_pos = *ppos;
	iov_iter_init(&iter, WRITE, &iov, 1, len);

	ret = filp->f_op->write_iter(&kiocb, &iter);
	BUG_ON(ret == -EIOCBQUEUED);
	*ppos = kiocb.ki_pos;
	return ret;
}

EXPORT_SYMBOL(new_sync_write);

ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
{
	mm_segment_t old_fs;
	const char __user *p;
	ssize_t ret;

	if (!(file->f_mode & FMODE_CAN_WRITE))
		return -EINVAL;

	old_fs = get_fs();
	set_fs(get_ds());
	p = (__force const char __user *)buf;
	if (count > MAX_RW_COUNT)
		count =  MAX_RW_COUNT;
	if (file->f_op->write)
		ret = file->f_op->write(file, p, count, pos);
	else if (file->f_op->aio_write)
		ret = do_sync_write(file, p, count, pos);
	else
		ret = new_sync_write(file, p, count, pos);
	set_fs(old_fs);
	if (ret > 0) {
		fsnotify_modify(file);
		add_wchar(current, ret);
	}
	inc_syscw(current);
	return ret;
}

EXPORT_SYMBOL(__kernel_write);

ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
{
	ssize_t ret;

	if (!(file->f_mode & FMODE_WRITE))
		return -EBADF;
	if (!(file->f_mode & FMODE_CAN_WRITE))
		return -EINVAL;
	if (unlikely(!access_ok(VERIFY_READ, buf, count)))
		return -EFAULT;

	ret = rw_verify_area(WRITE, file, pos, count);
	if (ret >= 0) {
		count = ret;
		file_start_write(file);
		if (file->f_op->write)
			ret = file->f_op->write(file, buf, count, pos);
		else if (file->f_op->aio_write)
			ret = do_sync_write(file, buf, count, pos);
		else
			ret = new_sync_write(file, buf, count, pos);
		if (ret > 0) {
			fsnotify_modify(file);
			add_wchar(current, ret);
		}
		inc_syscw(current);
		file_end_write(file);
	}

	return ret;
}