fs/ioctl.c

   1 /*
   2  *  linux/fs/ioctl.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/mm.h>
   8 #include <linux/smp_lock.h>
   9 #include <linux/file.h>
  10
  11 #include <asm/uaccess.h>
  12
  13 static int file_ioctl(struct file *filp,unsigned int cmd,unsigned long arg)
  14 {
  15         int error;
  16         int block;
  17         struct inode * inode = filp->f_dentry->d_inode;
  18
  19         switch (cmd) {
  20                 case FIBMAP:
  21                         if (inode->i_op == NULL)
  22                                 return -EBADF;
  23                         if (inode->i_op->bmap == NULL)
  24                                 return -EINVAL;
  25                         if ((error = get_user(block, (int *) arg)) != 0)
  26                                 return error;
  27                         block = inode->i_op->bmap(inode,block);
  28                         return put_user(block, (int *) arg);
  29                 case FIGETBSZ:
  30                         if (inode->i_sb == NULL)
  31                                 return -EBADF;
  32                         return put_user(inode->i_sb->s_blocksize, (int *) arg);
  33                 case FIONREAD:
  34                         return put_user(inode->i_size - filp->f_pos, (int *) arg);
  35         }
  36         if (filp->f_op && filp->f_op->ioctl)
  37                 return filp->f_op->ioctl(inode, filp, cmd, arg);
  38         return -ENOTTY;
  39 }
  40
  41
  42 asmlinkage int sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
  43 {
  44         struct file * filp;
  45         unsigned int flag;
  46         int on, error = -EBADF;
  47
  48         lock_kernel();
  49         filp = fget(fd);
  50         if (!filp)
  51                 goto out;
  52         error = 0;
  53         switch (cmd) {
  54                 case FIOCLEX:
  55                         FD_SET(fd, &current->files->close_on_exec);
  56                         break;
  57
  58                 case FIONCLEX:
  59                         FD_CLR(fd, &current->files->close_on_exec);
  60                         break;
  61
  62                 case FIONBIO:
  63                         if ((error = get_user(on, (int *)arg)) != 0)
  64                                 break;
  65                         flag = O_NONBLOCK;
  66 #ifdef __sparc__
  67                         /* SunOS compatibility item. */
  68                         if(O_NONBLOCK != O_NDELAY)
  69                                 flag |= O_NDELAY;
  70 #endif
  71                         if (on)
  72                                 filp->f_flags |= flag;
  73                         else
  74                                 filp->f_flags &= ~flag;
  75                         break;
  76
  77                 case FIOASYNC:
  78                         if ((error = get_user(on, (int *)arg)) != 0)
  79                                 break;
  80                         flag = on ? FASYNC : 0;
  81
  82                         /* Did FASYNC state change ? */
  83                         if ((flag ^ filp->f_flags) & FASYNC) {
  84                                 if (filp->f_op && filp->f_op->fasync)
  85                                         filp->f_op->fasync(fd, filp, on);
  86                         }
  87                         if (on)
  88                                 filp->f_flags |= FASYNC;
  89                         else
  90                                 filp->f_flags &= ~FASYNC;
  91                         break;
  92
  93                 default:
  94                         error = -ENOTTY;
  95                         if (!filp->f_dentry || !filp->f_dentry->d_inode)
  96                                 error = -ENOENT;
  97                         else if (S_ISREG(filp->f_dentry->d_inode->i_mode))
  98                                 error = file_ioctl(filp, cmd, arg);
  99                         else if (filp->f_op && filp->f_op->ioctl)
 100                                 error = filp->f_op->ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
 101         }
 102         fput(filp);
 103
 104 out:
 105         unlock_kernel();
 106         return error;
 107 }