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 buffer_head tmp;
  23
  24                         if (inode->i_op == NULL)
  25                                 return -EBADF;
  26                         if (inode->i_op->get_block == NULL)
  27                                 return -EINVAL;
  28                         if (!capable(CAP_SYS_RAWIO))
  29                                 return -EPERM;
  30                         if ((error = get_user(block, (int *) arg)) != 0)
  31                                 return error;
  32
  33                         tmp.b_state = 0;
  34                         tmp.b_blocknr = 0;
  35                         inode->i_op->get_block(inode, block, &tmp, 0);
  36                         return put_user(tmp.b_blocknr, (int *) arg);
  37                 }
  38                 case FIGETBSZ:
  39                         if (inode->i_sb == NULL)
  40                                 return -EBADF;
  41                         return put_user(inode->i_sb->s_blocksize, (int *) arg);
  42                 case FIONREAD:
  43                         return put_user(inode->i_size - filp->f_pos, (int *) arg);
  44         }
  45         if (filp->f_op && filp->f_op->ioctl)
  46                 return filp->f_op->ioctl(inode, filp, cmd, arg);
  47         return -ENOTTY;
  48 }
  49
  50
  51 asmlinkage int sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
  52 {
  53         struct file * filp;
  54         unsigned int flag;
  55         int on, error = -EBADF;
  56
  57         filp = fget(fd);
  58         if (!filp)
  59                 goto out;
  60         error = 0;
  61         lock_kernel();
  62         switch (cmd) {
  63                 case FIOCLEX:
  64                         FD_SET(fd, current->files->close_on_exec);
  65                         break;
  66
  67                 case FIONCLEX:
  68                         FD_CLR(fd, current->files->close_on_exec);
  69                         break;
  70
  71                 case FIONBIO:
  72                         if ((error = get_user(on, (int *)arg)) != 0)
  73                                 break;
  74                         flag = O_NONBLOCK;
  75 #ifdef __sparc__
  76                         /* SunOS compatibility item. */
  77                         if(O_NONBLOCK != O_NDELAY)
  78                                 flag |= O_NDELAY;
  79 #endif
  80                         if (on)
  81                                 filp->f_flags |= flag;
  82                         else
  83                                 filp->f_flags &= ~flag;
  84                         break;
  85
  86                 case FIOASYNC:
  87                         if ((error = get_user(on, (int *)arg)) != 0)
  88                                 break;
  89                         flag = on ? FASYNC : 0;
  90
  91                         /* Did FASYNC state change ? */
  92                         if ((flag ^ filp->f_flags) & FASYNC) {
  93                                 if (filp->f_op && filp->f_op->fasync)
  94                                         filp->f_op->fasync(fd, filp, on);
  95                         }
  96                         if (on)
  97                                 filp->f_flags |= FASYNC;
  98                         else
  99                                 filp->f_flags &= ~FASYNC;
 100                         break;
 101
 102                 default:
 103                         error = -ENOTTY;
 104                         if (!filp->f_dentry || !filp->f_dentry->d_inode)
 105                                 error = -ENOENT;
 106                         else if (S_ISREG(filp->f_dentry->d_inode->i_mode))
 107                                 error = file_ioctl(filp, cmd, arg);
 108                         else if (filp->f_op && filp->f_op->ioctl)
 109                                 error = filp->f_op->ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
 110         }
 111         fput(filp);
 112         unlock_kernel();
 113
 114 out:
 115         return error;
 116 }