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                 {
  22                         struct address_space *mapping = inode->i_mapping;
  23                         int res;
  24                         /* do we support this mess? */
  25                         if (!mapping->a_ops->bmap)
  26                                 return -EINVAL;
  27                         if (!capable(CAP_SYS_RAWIO))
  28                                 return -EPERM;
  29                         if ((error = get_user(block, (int *) arg)) != 0)
  30                                 return error;
  31
  32                         res = mapping->a_ops->bmap(mapping, block);
  33                         return put_user(res, (int *) arg);
  34                 }
  35                 case FIGETBSZ:
  36                         if (inode->i_sb == NULL)
  37                                 return -EBADF;
  38                         return put_user(inode->i_sb->s_blocksize, (int *) arg);
  39                 case FIONREAD:
  40                         return put_user(inode->i_size - filp->f_pos, (int *) arg);
  41         }
  42         if (filp->f_op && filp->f_op->ioctl)
  43                 return filp->f_op->ioctl(inode, filp, cmd, arg);
  44         return -ENOTTY;
  45 }
  46
  47
  48 asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
  49 {
  50         struct file * filp;
  51         unsigned int flag;
  52         int on, error = -EBADF;
  53
  54         filp = fget(fd);
  55         if (!filp)
  56                 goto out;
  57         error = 0;
  58         lock_kernel();
  59         switch (cmd) {
  60                 case FIOCLEX:
  61                         FD_SET(fd, current->files->close_on_exec);
  62                         break;
  63
  64                 case FIONCLEX:
  65                         FD_CLR(fd, current->files->close_on_exec);
  66                         break;
  67
  68                 case FIONBIO:
  69                         if ((error = get_user(on, (int *)arg)) != 0)
  70                                 break;
  71                         flag = O_NONBLOCK;
  72 #ifdef __sparc__
  73                         /* SunOS compatibility item. */
  74                         if(O_NONBLOCK != O_NDELAY)
  75                                 flag |= O_NDELAY;
  76 #endif
  77                         if (on)
  78                                 filp->f_flags |= flag;
  79                         else
  80                                 filp->f_flags &= ~flag;
  81                         break;
  82
  83                 case FIOASYNC:
  84                         if ((error = get_user(on, (int *)arg)) != 0)
  85                                 break;
  86                         flag = on ? FASYNC : 0;
  87
  88                         /* Did FASYNC state change ? */
  89                         if ((flag ^ filp->f_flags) & FASYNC) {
  90                                 if (filp->f_op && filp->f_op->fasync)
  91                                         error = filp->f_op->fasync(fd, filp, on);
  92                                 else error = -ENOTTY;
  93                         }
  94                         if (error != 0)
  95                                 break;
  96
  97                         if (on)
  98                                 filp->f_flags |= FASYNC;
  99                         else
 100                                 filp->f_flags &= ~FASYNC;
 101                         break;
 102
 103                 default:
 104                         error = -ENOTTY;
 105                         if (S_ISREG(filp->f_dentry->d_inode->i_mode))
 106                                 error = file_ioctl(filp, cmd, arg);
 107                         else if (filp->f_op && filp->f_op->ioctl)
 108                                 error = filp->f_op->ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
 109         }
 110         fput(filp);
 111         unlock_kernel();
 112
 113 out:
 114         return error;
 115 }