/* *  linux/fs/ioctl.c * *  Copyright (C) 1991, 1992  Linus Torvalds */ #include <linux/config.h>#include <linux/syscalls.h>#include <linux/mm.h>#include <linux/smp_lock.h>#include <linux/capability.h>#include <linux/file.h>#include <linux/fs.h>#include <linux/security.h>#include <linux/module.h> #include <asm/uaccess.h>#include <asm/ioctls.h> static long do_ioctl(struct file *filp, unsigned int cmd,		unsigned long arg){	int error = -ENOTTY; 	if (!filp->f_op)		goto out; 	if (filp->f_op->unlocked_ioctl) {		error = filp->f_op->unlocked_ioctl(filp, cmd, arg);		if (error == -ENOIOCTLCMD)			error = -EINVAL;		goto out;	} else if (filp->f_op->ioctl) {		lock_kernel();		error = filp->f_op->ioctl(filp->f_dentry->d_inode,					  filp, cmd, arg);		unlock_kernel();	}  out:	return error;} static int file_ioctl(struct file *filp, unsigned int cmd,		unsigned long arg){	int error;	int block;	struct inode * inode = filp->f_dentry->d_inode;	int __user *p = (int __user *)arg; 	switch (cmd) {		case FIBMAP:		{			struct address_space *mapping = filp->f_mapping;			int res;			/* do we support this mess? */			if (!mapping->a_ops->bmap)				return -EINVAL;			if (!capable(CAP_SYS_RAWIO))				return -EPERM;			if ((error = get_user(block, p)) != 0)				return error; 			lock_kernel();			res = mapping->a_ops->bmap(mapping, block);			unlock_kernel();			return put_user(res, p);		}		case FIGETBSZ:			if (inode->i_sb == NULL)				return -EBADF;			return put_user(inode->i_sb->s_blocksize, p);		case FIONREAD:			return put_user(i_size_read(inode) - filp->f_pos, p);	} 	return do_ioctl(filp, cmd, arg);} /* * When you add any new common ioctls to the switches above and below * please update compat_sys_ioctl() too. * * vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d. * It's just a simple helper for sys_ioctl and compat_sys_ioctl. */int vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned long arg){	unsigned int flag;	int on, error = 0; 	switch (cmd) {		case FIOCLEX:			set_close_on_exec(fd, 1);			break; 		case FIONCLEX:			set_close_on_exec(fd, 0);			break; 		case FIONBIO:			if ((error = get_user(on, (int __user *)arg)) != 0)				break;			flag = O_NONBLOCK;#ifdef __sparc__			/* SunOS compatibility item. */			if(O_NONBLOCK != O_NDELAY)				flag |= O_NDELAY;#endif			if (on)				filp->f_flags |= flag;			else				filp->f_flags &= ~flag;			break; 		case FIOASYNC:			if ((error = get_user(on, (int __user *)arg)) != 0)				break;			flag = on ? FASYNC : 0; 			/* Did FASYNC state change ? */			if ((flag ^ filp->f_flags) & FASYNC) {				if (filp->f_op && filp->f_op->fasync) {					lock_kernel();					error = filp->f_op->fasync(fd, filp, on);					unlock_kernel();				}				else error = -ENOTTY;			}			if (error != 0)				break; 			if (on)				filp->f_flags |= FASYNC;			else				filp->f_flags &= ~FASYNC;			break; 		case FIOQSIZE:			if (S_ISDIR(filp->f_dentry->d_inode->i_mode) ||			    S_ISREG(filp->f_dentry->d_inode->i_mode) ||			    S_ISLNK(filp->f_dentry->d_inode->i_mode)) {				loff_t res = inode_get_bytes(filp->f_dentry->d_inode);				error = copy_to_user((loff_t __user *)arg, &res, sizeof(res)) ? -EFAULT : 0;			}			else				error = -ENOTTY;			break;		default:			if (S_ISREG(filp->f_dentry->d_inode->i_mode))				error = file_ioctl(filp, cmd, arg);			else				error = do_ioctl(filp, cmd, arg);			break;	}	return error;} asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg){	struct file * filp;	int error = -EBADF;	int fput_needed; 	filp = fget_light(fd, &fput_needed);	if (!filp)		goto out; 	error = security_file_ioctl(filp, cmd, arg);	if (error)		goto out_fput; 	error = vfs_ioctl(filp, fd, cmd, arg); out_fput:	fput_light(filp, fput_needed); out:	return error;} /* * Platforms implementing 32 bit compatibility ioctl handlers in * modules need this exported */#ifdef CONFIG_COMPATEXPORT_SYMBOL(sys_ioctl);#endif