fs/coda/pioctl.c

   1 /*
   2  * Pioctl operations for Coda.
   3  * Original version: (C) 1996 Peter Braam
   4  * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
   5  *
   6  * Carnegie Mellon encourages users of this code to contribute improvements
   7  * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/time.h>
  13 #include <linux/fs.h>
  14 #include <linux/stat.h>
  15 #include <linux/errno.h>
  16 #include <linux/string.h>
  17 #include <linux/namei.h>
  18 #include <linux/module.h>
  19 #include <asm/uaccess.h>
  20
  21 #include <linux/coda.h>
  22 #include <linux/coda_psdev.h>
  23
  24 #include "coda_linux.h"
  25
  26 /* pioctl ops */
  27 static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags);
  28 static long coda_pioctl(struct file *filp, unsigned int cmd,
  29                         unsigned long user_data);
  30
  31 /* exported from this file */
  32 const struct inode_operations coda_ioctl_inode_operations = {
  33         .permission     = coda_ioctl_permission,
  34         .setattr        = coda_setattr,
  35 };
  36
  37 const struct file_operations coda_ioctl_operations = {
  38         .owner          = THIS_MODULE,
  39         .unlocked_ioctl = coda_pioctl,
  40         .llseek         = noop_llseek,
  41 };
  42
  43 /* the coda pioctl inode ops */
  44 static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags)
  45 {
  46         if (flags & IPERM_FLAG_RCU)
  47                 return -ECHILD;
  48         return (mask & MAY_EXEC) ? -EACCES : 0;
  49 }
  50
  51 static long coda_pioctl(struct file *filp, unsigned int cmd,
  52                         unsigned long user_data)
  53 {
  54         struct path path;
  55         int error;
  56         struct PioctlData data;
  57         struct inode *inode = filp->f_dentry->d_inode;
  58         struct inode *target_inode = NULL;
  59         struct coda_inode_info *cnp;
  60
  61         /* get the Pioctl data arguments from user space */
  62         if (copy_from_user(&data, (void __user *)user_data, sizeof(data)))
  63                 return -EINVAL;
  64
  65         /*
  66          * Look up the pathname. Note that the pathname is in
  67          * user memory, and namei takes care of this
  68          */
  69         if (data.follow)
  70                 error = user_path(data.path, &path);
  71         else
  72                 error = user_lpath(data.path, &path);
  73
  74         if (error)
  75                 return error;
  76
  77         target_inode = path.dentry->d_inode;
  78
  79         /* return if it is not a Coda inode */
  80         if (target_inode->i_sb != inode->i_sb) {
  81                 error = -EINVAL;
  82                 goto out;
  83         }
  84
  85         /* now proceed to make the upcall */
  86         cnp = ITOC(target_inode);
  87
  88         error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
  89 out:
  90         path_put(&path);
  91         return error;
  92 }