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/*
* linux/fs/ioctl.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#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 <linux/uaccess.h>
#include <asm/ioctls.h>
/**
* vfs_ioctl - call filesystem specific ioctl methods
* @filp: [in] open file to invoke ioctl method on
* @cmd: [in] ioctl command to execute
* @arg: [in/out] command-specific argument for ioctl
*
* Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
* invokes * filesystem specific ->ioctl method. If neither method exists,
* returns -ENOTTY.
*
* Returns 0 on success, -errno on error.
*/
long vfs_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_path.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_path.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;
error = get_user(block, p);
if (error)
return error;
lock_kernel();
res = mapping->a_ops->bmap(mapping, block);
unlock_kernel();
return put_user(res, p);
}
case FIGETBSZ:
return put_user(inode->i_sb->s_blocksize, p);
case FIONREAD:
return put_user(i_size_read(inode) - filp->f_pos, p);
}
return vfs_ioctl(filp, cmd, arg);
}
/*
* When you add any new common ioctls to the switches above and below
* please update compat_sys_ioctl() too.
*
* do_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 do_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:
error = get_user(on, (int __user *)arg);
if (error)
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:
error = get_user(on, (int __user *)arg);
if (error)
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_path.dentry->d_inode->i_mode) ||
S_ISREG(filp->f_path.dentry->d_inode->i_mode) ||
S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) {
loff_t res =
inode_get_bytes(filp->f_path.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_path.dentry->d_inode->i_mode))
error = file_ioctl(filp, cmd, arg);
else
error = vfs_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 = do_vfs_ioctl(filp, fd, cmd, arg);
out_fput:
fput_light(filp, fput_needed);
out:
return error;
}
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